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Associate - Estate Litigation

Contact John
Phone: 519.660.7808
Fax: 416.594.4391

John is an associate in Siskinds’ general litigation group. John’s practice focuses on all areas of estate and capacity litigation.

Education

Western University, B.A.
University of Ottawa, J.D.

Called to the Bar in 2016
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About

John is a third-generation lawyer who practices in Siskinds’ general litigation group. John obtained his J.D. at the University of Ottawa, Faculty of Law, in 2015 and was called to the bar in 2016.

John joined Siskinds as an associate in February of 2021. Prior to joining Siskinds, John was an associate at a prominent law firm located in Brantford, Ontario, where he developed a passion for estate litigation, resolving power of attorney disputes and addressing issues that arise during the administration of estates. John’s practice focuses primarily on estate litigation, guardianship applications, and power of attorney disputes. John has represented clients at various levels of court in Ontario including the Court of Appeal, the Superior Court of Justice, and Small Claims Court. John was named on the 2024 and 2025 Best Lawyers™: Ones to Watch in Canada list, which recognizes Canadian lawyers who are earlier in their careers for outstanding professional excellence.

Prior to law school, John attended King’s University College at Western University. While John was a student at King’s University College, he was a member of the Western University’s Men’s varsity soccer team, which participated in several provincial championships and two national championships. While at King’s, John was a two-time academic All-Canadian and was consistently on the Dean’s honor list.

In his spare time, John enjoys exercising and spending time with his wife and daughter, and his four-legged companions, Walter and Frank.

Client Testimonials

Highly recommend John and his entire team
I had a great experience with John Morrissey and his team at Siskinds. I was in a same sex common law relationship and required his help with a dependent support claim. John made my first time experience dealing with a lawyer an easy one. He was very knowledgeable and he and his law clerk Adam were always available to answer any questions or concerns I may have. I would highly recommend John and his entire team at Siskinds. - R.S.

The outcome was just what I wanted
I obtained Paul Morrissey to challenge my mother's last will. He put John Morrissey on my case, and I know that was the right choice for me. Although it took a few years, the outcome was just what I wanted. John was always very professional and respectful towards me. He always addressed my concerns and talked me through any issues I had. I would highly recommend him to anyone that needed help with estate issues. He is very knowledgeable and goes though the right steps to get the job done. - C.C.

Patient, knowledgeable and quick to respond to our questions
We obtained John Morrissey to assist us in obtaining Guardianship over my Father-in-law. Him & his staff were always very patient, knowledgeable and quick to respond to our questions, no matter how simple or complicated they were. This really helped make a difficult situation feel much less stressful. He was also very helpful in arranging service of the Application Record to Jamaica which made things so much easier as well. We would highly recommend his services to help give you the same peace of mind he gave us, so we are able to better care for our loved ones financial and personal affairs. Thanks John. - J.G.

I highly recommend John
John Morrissey Estate lawyer with Siskinds LLP helped resolve Will challenge/estate dispute. Extremely impressed with results John has provided for me. John is professional, supportive, John answered questions and concerns I had promptly and with clarity every step of the way. I highly recommend John. - T.Y.

He knew exactly what needed to be done, and how to do it
After my sister died in the UK, I called John Morrissey at Siskinds LLP. Although my sister died in the UK and I obtained probate in the UK, I needed help from a lawyer in Ontario because my sister owned assets in Canada that I could not access with the probate issued by the UK Court. After some research, I discovered that I needed to reseal the UK probate here in Ontario. When I contacted John, he knew exactly what needed to be done, and how to do it. John Morrissey and Heather Whitty were able to guide and assist me with resealing probate in a timely fashion, keeping me informed and updated all the way along. This required John and Heather to collect information/documentation from the UK, correspond with my solicitors in the UK and with representatives at financial institutions in the UK and Canada, and ultimately file documents with the Ontario Superior Court of Justice. With Heather and John’s assistance, I was able to obtain an Order from the Ontario Superior Court of Justice resealing the UK probate. This allowed me to gain access to the assets owned by my sister here in Ontario, which brought me one step closer to finalizing the administration of my sister’s estate, which was a major relief to me and my family. If you ever need assistance with resealing probate granted in the UK, I strongly recommend that you contact John and his team at Siskinds. I had a wonderful experience. - H.B

I was impressed with John’s manner, inter personal skills and knowledge
Since my first meeting with John Morrissey, we have worked together on 3 significant Estate files regarding myself, and our family’s affairs. There is one more future file pending, eventually to be settled, and John will be handling that for us.

John had just passed the Bar ( circa 2015 – 2016 ) and was working with a Partner, who was handling a $225K matter that I was very involved with. I was impressed with John’s manner, inter personal skills and knowledge. We were successful in settling the matter for the whole amount.

About 2018 I was confronted with my wife’s father’s Estate matters. My now deceased wife was incapacitated, residing in Long Term Care. As her POA, I had to lead the resolution of the matter. My wife’s step family members had, against specific terms of the father’s Will, stolen the 3 children’s share of their deceased father’s matrimonial home. My wife and her two brothers were all entitled to a 33% share of 50% of the matrimonial home. The value for each was in the $200k+ range.

The step family sold the original matrimonial house and put the new house 100% in just the stepmother’s name. Title should have included her father’s Estate. This was a gross failure on the part of many parties. John was not involved in that sale and purchase transaction. I specifically asked for John to lead the file. Sure enough, he fully resolved the matter. We are now 100% assured to have that property value, which is now in the $250K range. Without John’s help, I would have had a major legal battle to get the monies owing from the stepmother’s estate.

This past August 2023, John settled a very contentious Estate file concerning my wife’s mother’s Estate. The matter involved our daughters. Given that my wife passed before her mother, our daughters were entitled to receive the value, not myself. Given the mother’s dementia, and alleged coercion by the brothers to change the original Will in their favor only, our daughters were being 100% “cheated” out of their mother’s share of the Estate. John resolved the $150K share of the matter with a very satisfactory settlement, out of court.

If you are in Estate litigation, it is because your appropriate share of an Estate is being challenged. It is amazing to what extent family will go the get a “bigger piece of the pie” than they are entitled to. If John had not resolved these matters for us, we would have been out of hundreds of thousands of dollars that we were legally and legitimately entitled to.

I am privileged to recommend John Morrissey. - R.H.

Being referred to Mr. Morrissey was the best advice anyone could have given us
I was referred to Siskinds LLP by another law firm I was using. It was felt that John Morrissey's expertise would be of great benefit to helping us with the legal roadblock we encountered. It seemed that my specific situation warranted someone with expertise in Estate Litigation, Guardianship, Separation Agreements, and even the enforcement of such matters post-mortem. Being referred to Mr. Morrissey was the best advice anyone could have given us. During our first contact with John he guided us with professionalism, compassion and kindness, and truly answered all of our questions. He put our worries at ease and explained a clear path forward. He was responsive to our emails and questions, gave us realistic timelines, and handled all aspects of legal process with sound advice. His professionalism was much appreciated, and we would have to admit, he is also an excellent listener... because let's face it... sometimes these situations arise with emotions in tow. I can say for certain that I will be calling on John Morrissey, and his wonderful partner Reenya Koshaba for any future needs, and recommending him to my close family and friends. - M.G.

I highly recommend John and his team
I recently retained John Morrissey in what for me was an overwhelming task of proceeding with a Guardianship Application. From our first telephone call, John settled my concerns and shed light on the process with kindness, efficiency and his knowledge on the subject was evident. When I needed to contact either John or Reenya, my questions were addressed promptly and the attention to detail in their work was evident. I was kept informed of the developments during the application process and it provided relief to have this task dealt with in such an impeccable manner. I highly recommend John and his team at Siskinds LLP for Guardianship applications and similar matters. - M.P.

Kindness and empathy
This year my family became involved in contentious estate litigation, being sued for dependent support plus a large portion of the estate assets. As the estate trustee I was compelled to defend the estate on behalf of the beneficiaries. As a result I was referred to Siskinds LLP and John Morrissey whose legal expertise is estate litigation. From my first meeting with John until the resolution of the matter, I found him to be responsive and accessible. John and his team responded to my questions and concerns in a timely manner, being very able to explain legal processes strategies well to a lay person. John’s legal expertise was complemented by his kindness and empathy. He made a trying and difficult experience better. I would highly recommend John Morrissey and Siskinds LLP to anyone dealing with an estate challenge. – J.B.

Such a weight off of my shoulders
I recently retained John Morrissey in a Co Power of Attorney matter and I couldn't be happier with my decision to do this. Every email I sent as well as every phone call I made was returned to me instantly. My matter was resolved within days of retaining John. He handled my case with seriousness, forcefulness and professionalism. He took such a weight off of my shoulders and I never felt alone through this ordeal. I would recommend this law firm and John to anyone. If I ever have a problem to deal with again; Siskinds will be my go to every time. - S.G.

Above and beyond
Siskinds is by far the best law firm in London. I contacted them concerning an estate matter. John Morrissey and his assistant Reenya Koshaba, were there every step of the way. They were detail orientated and I was kept up to date throughout. Most importantly though, he effectively solved our problem. John's performance (and team) was above and beyond expectation. I couldn't have asked for more. - M.D.

A huge help
We had been dealing with an estate issue for a year and a half when the other law firm told us we would need to contact a second lawyer to get the issues resolved. We were referred to John Morrissey, and he was a HUGE help. He kept us informed as to the steps he was taking and the progress being made with the issue. He communicated with us regularly and clearly, without all the "legalize". We'd probably still be stuck in limbo without his help. Great job. - S.C.

Kind, patient and professional
I first contacted Siskinds LLP in June of 2021 to speak with a lawyer concerning a potential estate litigation matter. Shortly after contacting Siskinds, John Morrissey met with me to discuss my legal matter in great detail and on very short notice. Prior to contacting John I also consulted with another experienced lawyer on the same issue, however after speaking with John and hearing his position on how he would approach the issue- I decided to retain Mr. Morrissey. I am very thankful that I did so. John quickly and efficiently resolved my independent support issue and helped me achieve a great result at a fair price (all without having to go to court). Throughout the course of our working relationship, John was kind, patient and professional. He took time to explain the legal principles at play in my matter, not only to me but also to my children through conference calls and strongly advocated for my position from start to finish. He was cordial with opposing counsel and was results oriented. John's assistant Reenya Koshaba and his clerk, Heather Whitty, were responsive and detail oriented and were of great assistance in moving the matter forward expeditiously. I strongly recommend John Morrissey and the estate litigation team at Siskinds for any of your estate litigation needs. - M.P.

Knowledgeable and professional
John Morrissey represented me in a co-power of attorney dispute. He went above and beyond to help me to feel at ease and supported when I was overwhelmed during the process. He was knowledgeable and professional and worked hard on my case.
He kept me informed during the whole time, and I know without John I would not have has the successful outcome. He stood by my requests and guided me through the process. John was a confident presence and walked the extra mile!!
I highly recommend John, I could not of asked for more. Thank you John Morrissey for absolutely everything. - S.K.

Professionalism, responsiveness, and expertise exceeded my expectations
I am so thankful to have connected with John [Morrissey] who helped solve our chaotic legal difficulty last summer. I chose Siskinds simply through an online search for local Estate Law. John responded to my general inquiry in a timely manner and presented himself on the phone in a way that invoked confidence and trust. The expertise evident in that initial call was authentic.
John’s kindness, attention to detail, and great skill was so appreciated as we maneuvered a messy family situation. Through the long course of events, I could always count on John to be on top of things, never miss deadlines or important actions, keep me informed, explain procedures, and be patient with various oddities of the family situation. John’s professionalism, responsiveness, and expertise exceeded my expectations. John’s skill in dealing with the argumentative party was exceptional. I will also add, that both Reenya Koshaba and Heather Whitty were extremely helpful, thorough, and detailed in all their work and responses.
I will endorse both Siskinds and John Morrissey to anyone in need of legal assistance. I cannot express enough my gratitude and relief for John’s help in resolving this emotional family controversy. - D.W.

Memberships and Associations

  • Law Society of Ontario
  • Ontario Bar Association
  • Middlesex Law Association

Awards and Recognition

John Morrissey has been selected by his peers for inclusion in Best Lawyers™: Ones to Watch in Canada 2024 and 2025.

Notable Work and Decisions

  • Markham Village Shoppes Limited v. Gino's Pizza Ltd., 2018 ONCA 746 (CanLII)
  • 2018 ONCA 782 (CanLII) | Markham Village Shoppes Limited v. Gino's Pizza Ltd. | CanLII
  • 2019 ONSC 4343 (CanLII) | Huntjens v. Obradovic | CanLII

John is a third-generation lawyer who practices in Siskinds’ general litigation group. John obtained his J.D. at the University of Ottawa, Faculty of Law, in 2015 and was called to the bar in 2016.

John joined Siskinds as an associate in February of 2021. Prior to joining Siskinds, John was an associate at a prominent law firm located in Brantford, Ontario, where he developed a passion for estate litigation, resolving power of attorney disputes and addressing issues that arise during the administration of estates. John’s practice focuses primarily on estate litigation, guardianship applications, and power of attorney disputes. John has represented clients at various levels of court in Ontario including the Court of Appeal, the Superior Court of Justice, and Small Claims Court. John was named on the 2024 and 2025 Best Lawyers™: Ones to Watch in Canada list, which recognizes Canadian lawyers who are earlier in their careers for outstanding professional excellence.

Prior to law school, John attended King’s University College at Western University. While John was a student at King’s University College, he was a member of the Western University’s Men’s varsity soccer team, which participated in several provincial championships and two national championships. While at King’s, John was a two-time academic All-Canadian and was consistently on the Dean’s honor list.

In his spare time, John enjoys exercising and spending time with his wife and daughter, and his four-legged companions, Walter and Frank.

Highly recommend John and his entire team
I had a great experience with John Morrissey and his team at Siskinds. I was in a same sex common law relationship and required his help with a dependent support claim. John made my first time experience dealing with a lawyer an easy one. He was very knowledgeable and he and his law clerk Adam were always available to answer any questions or concerns I may have. I would highly recommend John and his entire team at Siskinds. - R.S.

The outcome was just what I wanted
I obtained Paul Morrissey to challenge my mother's last will. He put John Morrissey on my case, and I know that was the right choice for me. Although it took a few years, the outcome was just what I wanted. John was always very professional and respectful towards me. He always addressed my concerns and talked me through any issues I had. I would highly recommend him to anyone that needed help with estate issues. He is very knowledgeable and goes though the right steps to get the job done. - C.C.

Patient, knowledgeable and quick to respond to our questions
We obtained John Morrissey to assist us in obtaining Guardianship over my Father-in-law. Him & his staff were always very patient, knowledgeable and quick to respond to our questions, no matter how simple or complicated they were. This really helped make a difficult situation feel much less stressful. He was also very helpful in arranging service of the Application Record to Jamaica which made things so much easier as well. We would highly recommend his services to help give you the same peace of mind he gave us, so we are able to better care for our loved ones financial and personal affairs. Thanks John. - J.G.

I highly recommend John
John Morrissey Estate lawyer with Siskinds LLP helped resolve Will challenge/estate dispute. Extremely impressed with results John has provided for me. John is professional, supportive, John answered questions and concerns I had promptly and with clarity every step of the way. I highly recommend John. - T.Y.

He knew exactly what needed to be done, and how to do it
After my sister died in the UK, I called John Morrissey at Siskinds LLP. Although my sister died in the UK and I obtained probate in the UK, I needed help from a lawyer in Ontario because my sister owned assets in Canada that I could not access with the probate issued by the UK Court. After some research, I discovered that I needed to reseal the UK probate here in Ontario. When I contacted John, he knew exactly what needed to be done, and how to do it. John Morrissey and Heather Whitty were able to guide and assist me with resealing probate in a timely fashion, keeping me informed and updated all the way along. This required John and Heather to collect information/documentation from the UK, correspond with my solicitors in the UK and with representatives at financial institutions in the UK and Canada, and ultimately file documents with the Ontario Superior Court of Justice. With Heather and John’s assistance, I was able to obtain an Order from the Ontario Superior Court of Justice resealing the UK probate. This allowed me to gain access to the assets owned by my sister here in Ontario, which brought me one step closer to finalizing the administration of my sister’s estate, which was a major relief to me and my family. If you ever need assistance with resealing probate granted in the UK, I strongly recommend that you contact John and his team at Siskinds. I had a wonderful experience. - H.B

I was impressed with John’s manner, inter personal skills and knowledge
Since my first meeting with John Morrissey, we have worked together on 3 significant Estate files regarding myself, and our family’s affairs. There is one more future file pending, eventually to be settled, and John will be handling that for us.

John had just passed the Bar ( circa 2015 – 2016 ) and was working with a Partner, who was handling a $225K matter that I was very involved with. I was impressed with John’s manner, inter personal skills and knowledge. We were successful in settling the matter for the whole amount.

About 2018 I was confronted with my wife’s father’s Estate matters. My now deceased wife was incapacitated, residing in Long Term Care. As her POA, I had to lead the resolution of the matter. My wife’s step family members had, against specific terms of the father’s Will, stolen the 3 children’s share of their deceased father’s matrimonial home. My wife and her two brothers were all entitled to a 33% share of 50% of the matrimonial home. The value for each was in the $200k+ range.

The step family sold the original matrimonial house and put the new house 100% in just the stepmother’s name. Title should have included her father’s Estate. This was a gross failure on the part of many parties. John was not involved in that sale and purchase transaction. I specifically asked for John to lead the file. Sure enough, he fully resolved the matter. We are now 100% assured to have that property value, which is now in the $250K range. Without John’s help, I would have had a major legal battle to get the monies owing from the stepmother’s estate.

This past August 2023, John settled a very contentious Estate file concerning my wife’s mother’s Estate. The matter involved our daughters. Given that my wife passed before her mother, our daughters were entitled to receive the value, not myself. Given the mother’s dementia, and alleged coercion by the brothers to change the original Will in their favor only, our daughters were being 100% “cheated” out of their mother’s share of the Estate. John resolved the $150K share of the matter with a very satisfactory settlement, out of court.

If you are in Estate litigation, it is because your appropriate share of an Estate is being challenged. It is amazing to what extent family will go the get a “bigger piece of the pie” than they are entitled to. If John had not resolved these matters for us, we would have been out of hundreds of thousands of dollars that we were legally and legitimately entitled to.

I am privileged to recommend John Morrissey. - R.H.

Being referred to Mr. Morrissey was the best advice anyone could have given us
I was referred to Siskinds LLP by another law firm I was using. It was felt that John Morrissey's expertise would be of great benefit to helping us with the legal roadblock we encountered. It seemed that my specific situation warranted someone with expertise in Estate Litigation, Guardianship, Separation Agreements, and even the enforcement of such matters post-mortem. Being referred to Mr. Morrissey was the best advice anyone could have given us. During our first contact with John he guided us with professionalism, compassion and kindness, and truly answered all of our questions. He put our worries at ease and explained a clear path forward. He was responsive to our emails and questions, gave us realistic timelines, and handled all aspects of legal process with sound advice. His professionalism was much appreciated, and we would have to admit, he is also an excellent listener... because let's face it... sometimes these situations arise with emotions in tow. I can say for certain that I will be calling on John Morrissey, and his wonderful partner Reenya Koshaba for any future needs, and recommending him to my close family and friends. - M.G.

I highly recommend John and his team
I recently retained John Morrissey in what for me was an overwhelming task of proceeding with a Guardianship Application. From our first telephone call, John settled my concerns and shed light on the process with kindness, efficiency and his knowledge on the subject was evident. When I needed to contact either John or Reenya, my questions were addressed promptly and the attention to detail in their work was evident. I was kept informed of the developments during the application process and it provided relief to have this task dealt with in such an impeccable manner. I highly recommend John and his team at Siskinds LLP for Guardianship applications and similar matters. - M.P.

Kindness and empathy
This year my family became involved in contentious estate litigation, being sued for dependent support plus a large portion of the estate assets. As the estate trustee I was compelled to defend the estate on behalf of the beneficiaries. As a result I was referred to Siskinds LLP and John Morrissey whose legal expertise is estate litigation. From my first meeting with John until the resolution of the matter, I found him to be responsive and accessible. John and his team responded to my questions and concerns in a timely manner, being very able to explain legal processes strategies well to a lay person. John’s legal expertise was complemented by his kindness and empathy. He made a trying and difficult experience better. I would highly recommend John Morrissey and Siskinds LLP to anyone dealing with an estate challenge. – J.B.

Such a weight off of my shoulders
I recently retained John Morrissey in a Co Power of Attorney matter and I couldn't be happier with my decision to do this. Every email I sent as well as every phone call I made was returned to me instantly. My matter was resolved within days of retaining John. He handled my case with seriousness, forcefulness and professionalism. He took such a weight off of my shoulders and I never felt alone through this ordeal. I would recommend this law firm and John to anyone. If I ever have a problem to deal with again; Siskinds will be my go to every time. - S.G.

Above and beyond
Siskinds is by far the best law firm in London. I contacted them concerning an estate matter. John Morrissey and his assistant Reenya Koshaba, were there every step of the way. They were detail orientated and I was kept up to date throughout. Most importantly though, he effectively solved our problem. John's performance (and team) was above and beyond expectation. I couldn't have asked for more. - M.D.

A huge help
We had been dealing with an estate issue for a year and a half when the other law firm told us we would need to contact a second lawyer to get the issues resolved. We were referred to John Morrissey, and he was a HUGE help. He kept us informed as to the steps he was taking and the progress being made with the issue. He communicated with us regularly and clearly, without all the "legalize". We'd probably still be stuck in limbo without his help. Great job. - S.C.

Kind, patient and professional
I first contacted Siskinds LLP in June of 2021 to speak with a lawyer concerning a potential estate litigation matter. Shortly after contacting Siskinds, John Morrissey met with me to discuss my legal matter in great detail and on very short notice. Prior to contacting John I also consulted with another experienced lawyer on the same issue, however after speaking with John and hearing his position on how he would approach the issue- I decided to retain Mr. Morrissey. I am very thankful that I did so. John quickly and efficiently resolved my independent support issue and helped me achieve a great result at a fair price (all without having to go to court). Throughout the course of our working relationship, John was kind, patient and professional. He took time to explain the legal principles at play in my matter, not only to me but also to my children through conference calls and strongly advocated for my position from start to finish. He was cordial with opposing counsel and was results oriented. John's assistant Reenya Koshaba and his clerk, Heather Whitty, were responsive and detail oriented and were of great assistance in moving the matter forward expeditiously. I strongly recommend John Morrissey and the estate litigation team at Siskinds for any of your estate litigation needs. - M.P.

Knowledgeable and professional
John Morrissey represented me in a co-power of attorney dispute. He went above and beyond to help me to feel at ease and supported when I was overwhelmed during the process. He was knowledgeable and professional and worked hard on my case.
He kept me informed during the whole time, and I know without John I would not have has the successful outcome. He stood by my requests and guided me through the process. John was a confident presence and walked the extra mile!!
I highly recommend John, I could not of asked for more. Thank you John Morrissey for absolutely everything. - S.K.

Professionalism, responsiveness, and expertise exceeded my expectations
I am so thankful to have connected with John [Morrissey] who helped solve our chaotic legal difficulty last summer. I chose Siskinds simply through an online search for local Estate Law. John responded to my general inquiry in a timely manner and presented himself on the phone in a way that invoked confidence and trust. The expertise evident in that initial call was authentic.
John’s kindness, attention to detail, and great skill was so appreciated as we maneuvered a messy family situation. Through the long course of events, I could always count on John to be on top of things, never miss deadlines or important actions, keep me informed, explain procedures, and be patient with various oddities of the family situation. John’s professionalism, responsiveness, and expertise exceeded my expectations. John’s skill in dealing with the argumentative party was exceptional. I will also add, that both Reenya Koshaba and Heather Whitty were extremely helpful, thorough, and detailed in all their work and responses.
I will endorse both Siskinds and John Morrissey to anyone in need of legal assistance. I cannot express enough my gratitude and relief for John’s help in resolving this emotional family controversy. - D.W.

  • Law Society of Ontario
  • Ontario Bar Association
  • Middlesex Law Association

John Morrissey has been selected by his peers for inclusion in Best Lawyers™: Ones to Watch in Canada 2024 and 2025.

  • Markham Village Shoppes Limited v. Gino's Pizza Ltd., 2018 ONCA 746 (CanLII)
  • 2018 ONCA 782 (CanLII) | Markham Village Shoppes Limited v. Gino's Pizza Ltd. | CanLII
  • 2019 ONSC 4343 (CanLII) | Huntjens v. Obradovic | CanLII

Meet My Team

Heather Whitty

Law Clerk

Adam Norman

Law Clerk