Joseph Mark O'Regan

O’REGAN, J. Mark, CPA, FCPA
1945 – 2025

Mark O’Regan passed away peacefully in Calgary, Alberta, on June 27, 2025, shortly after celebrating his 80th birthday with family.

He is lovingly remembered by his children Luke (Samantha), Matt (Helen), Jake (Sarah), Paul (Diann), and Heather; and by his grandchildren Lola, Oscar, Clive, Lionel, Finley, Robyn, Bailey, Ridley, Max, Rex, and Bert. He is also survived by his siblings Jane, Anne, and John, and predeceased by his brother Patrick.

Mark enjoyed a distinguished 38-year career with Ernst & Young (formerly Clarkson Gordon), where he served as Vice Chairman and led several business units. He was known for his pragmatic leadership, technical expertise, and early advocacy for diversity and inclusion. He also served as Chairman of St. Joseph’s Hospital and Southdown, and held a doctorate from the University of Windsor.

He deeply cherished time spent with family and friends, both near and far, and embraced adventure and travel with joy throughout his retirement.

Cremation has taken place. A Celebration of Life will be held on Thursday, July 17, 2025, from 2:00–4:00 p.m. at St. George’s Golf and Country Club, 1668 Islington Avenue, Etobicoke.

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