Obituary of Denis O'Connor

O’CONNOR, DENIS ( Raymond Denis)

Denis O’Connor passed away peacefully on September 12, 2025 in his 97th year, in the care of his loving family. He is survived by his beloved wife Ursula,  recently celebrating 66 years of marriage, and by their children:  Brian (Sheli), Maureen (Gil d. 2005; Paul), Cathy (David), Eileen (Remy), Monica (Stephen); grandchildren Kaeli, Denis (Nicole), Keegan (Sara), Brennan, Nicole, Stephanie (Henry), Matt (Kaitlin), Connor (Rachel), Cara, Estelle, Marina, Claira, Justin; great grandchild Frederick.  Denis was born October 30, 1928, in Pickering, Ontario, son of Arthur and Margaret (Dalton) O’Connor. He is predeceased by his siblings George (RCAF), Marguerite, Patricia, Morgan, Helen, Gerri, Terry (Colleen), Maurice, Moira Ste Marie (Ron), Ursula’s siblings Fr. Carl, Sr. Theresa and Victor Matthews. Denis is survived by in-laws Paul (Patricia), Michael (Jan),Barbara Matthews and sister-in-law Marilyn O’Connor, Cousins and many nieces and nephews. Denis was proud of the heritage of his Irish rural roots and felt privileged to belong to the strong and dynamic O’Connor, Dalton and Matthews families.

Denis graduated with a Bachelor of Arts degree from St. Michael’s College, University of Toronto in 1949, then pursued studies in Veterinary Medicine, graduating in 1957 from the Ontario Veterinary College in Guelph. He always had great respect for animals and how they impact the lives of people. He felt privileged to be able to care for the health of animals during 50 years of veterinary practice and farming in the Stouffville area. Together with his brother Terry, they established a large animal practice where their clients became friends. 

Denis was very involved with his university and community affiliations and also served on committees for his professional association, the province of Ontario and his local municipality. These included the Stouffville Credit Union, the Royal Winter Fair, mentoring veterinary students and the Ontario Ministry of Agriculture and Food Farm Product Appeals Tribunal. Over the last decade, Denis was an active participant and published author with a research consortium focused on improving support for caregivers of individuals with dementia and strengthening their voices in the research process.

Faith and family were very important to Denis: he was a lifelong member of the Knights of Columbus and was actively involved in the development of St. Mark School and Church in Stouffville. As a father, Denis was a patient mentor who was knowledgeable, empathetic and consistently provided unwavering support. Grandpa Denis was happy, kind and curious, and greatly enjoyed watching the grandkids develop their lives.   Grandma Urs and Grandpa Denis are so proud of their 13 grandchildren and love them very much.

Denis & Ursula loved to travel and cherished their vacation time in Florida, memorable family trips, and their travels throughout the world with friends. Denis’ interests and passions were widespread and included sport, the arts, religion, agriculture,science and One Health. He also enjoyed a good game of bridge, watching the Jays and Raptors or playing Sudoku. Denis was grateful for the full, beautiful life he shared with his immediate and extended family and for the many friendships through family, faith, farming, education, community and most recently,staff and residents at Amica Unionville. With his friendly smile and warm personality, he genuinely loved to see people and strike up a chat. 

Raymond Denis Joseph O’Connor was a loving, devoted husband to his everlasting sweetheart, Ursula, an incredibly inspiring Dad and father-in-law, a sweet and thoughtful Grandpa, a cherished son, brother and brother-in-law, a proud uncle and a loyal friend who was deeply loved and will be greatly missed.

Visitation will be held at Dixon Garland Funeral Home, Markham, on Thursday, September 18, 2025 from 2:00-4:00 pm and from 6:00-8:00 pm. Mass of Christian burial will be celebrated at 10:30am on Friday, September 19, 2025 at St. Mark Church, Stouffville. Interment to follow at Resurrection Cemetery, Whitby.

 In Denis’ memory, donations  to Canadian Foodgrains Bank (https://donate.foodgrainsbank.ca) or a charity of your choice would be appreciated by the family.

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