Michael Post O’Neil

May 10, 1938 ~ April 7, 2026

Born in: Los Angeles, California
Resided in: Carmel, Indiana

Michael Post O’Neil of Manhattan Beach, CA was delivered to his eternal home with Christ on April 7, 2026, after a long battle with Alzheimer’s disease. He was 87 years old. He was surrounded by his wife, children and grandchildren and passed away peacefully in Carmel, IN.

He is preceded in death by his first wife of thirty-six years and mother of his three children Dorothy Camero O’Neil (1940-1998). He is survived by his second wife Sheila Ryan O’Neil, his three adult children: Kenneth M. O’Neil, Daniel R. O’Neil (wife Jennifer O’Neil) and Shannon O’Neil Deck (husband Michael Deck) and his eight grandchildren: Connor O’Neil, Collin O’Neil, Cameron O’Neil, Lindsey O’Neil, Bridget Calkins (husband Kaden Calkins), Mary Engleking (husband Max Engleking), Peter Deck and Patrick Deck.

He was the son of Henry A. O’Neil and Janice P. O’Neil of Rapid City South Dakota and Pasadena, CA. He was the eighth of nine children and is preceded in death by his brothers Patrick H. O’Neil, Thomas J. O’Neil, Henry A. O’Neil, Carlin L. O’Neil and sisters June O’Neil Mallard, Janice O’Neil Wolcott, Mary Ellen O’Neil Taylor. He is survived by his sister Kathleen O’Neil Curran.

He was born on May 10, 1938 in Los Angeles, CA. He attended St. Philip Catholic School, St. John’s Military Academy, Loyola High School and California State University of Los Angeles. Following his father’s premature death, his primary years were shaped by his days at St. John Military Academy, where he became the Cadet Major, and later at Loyola High School where he boarded and excelled in the football, debate, drama and choir programs. At age seventeen, he met his future wife Dorothy Camero on the steps of St. Brendan Catholic Church in Los Angeles, after attending mass with his friends. They were later married in that Church in 1962 and would raise their family in Hancock Park where Dorothy was raised. Mike was also a proud member of the U.S. Marine Corps Reserves and served as a Staff Sergeant for several years.

Following high school, Mike enrolled at California State University Los Angeles, where he majored in political science and worked at a large pharmaceutical distributor near downtown. He was later hired by AH Robbins and worked there as a senior account executive in pharmaceutical sales until 1971. In 1972, he founded O’Neil & Company, which specialized in providing financial services and real estate investment partnerships. In 1980 he formed new partnerships with several of his physician clients, which focused on opening and managing urgent care facilities in Southern California. He served as COO. The company later went public as US Medical Enterprises, before it was acquired by Concentra Health. Mike concluded his 42-year career, when he retired in 2003 in Manhattan Beach, CA.

Mike was a devoted husband to Dorothy and father to his children. Always early to rise and on task, he was his family’s constant source of energy and it’s true north star by always navigating the horizon, pushing forward and setting the example. His greatest joys were going to Mass on Sunday, proudly attending his children’s numerous events, grilling for family dinners on the patio and enjoying a good party or trip with friends. He was also a fixture in his community where he took leadership roles in several groups including Cathedral Chapel Catholic Parish, St. Brendan’s Catholic Parish, YMCA, Gardner Park Board, Pan Pacific Park Commission, Wilshire Baseball League, Loyola High School Booster Club, Kiwanis Children’s Fund and several other smaller groups supporting the Catholic Church’s mission in Los Angeles. Shortly before retirement, he lost his wife Dorothy to cancer in 1998.

During retirement, Mike continued his service as a senior leader of the LAX Kiwanis Club. It was here, that he met Sheila Ryan, an executive at Air New Zealand, who, in 2004, would become his second wife of twenty-one years. Sheila and Mike shared a very positive and adventurous outlook on life. Together, they were able to travel the world, create unforgettable memories and make many new friends. They were dedicated members of American Martyrs Catholic Parish in Manhattan Beach, where Mike served as a Eucharistic Minister, Knight of Columbus and a member of the Men’s Cornerstone Alumni for several years. In addition to playing golf and traveling while retired, his greatest joy was being a proud grandfather. “Da” and Sheila were affectionately embraced by his eight grandchildren and they proudly doted on them.

A.M.D.G.

A Catholic funeral mass and reception in his honor will be celebrated at American Martyrs Catholic Church in Manhattan Beach, CA on Thursday, April 30, 2026 at 2pm.

American Martyrs Catholic Church

1431 Deegan Place

Manhattan Beach CA 90266

His family will privately celebrate his Catholic interment at Calvary Cemetery in Los Angeles, CA on Friday, May 1.

Condolences may be sent to:

Mrs. Sheila O’Neil

15 Catalina Court

Manhattan Beach, CA 90266

Memorial gifts in the name of Michael P. O’Neil can be made to Loyola High School of Los Angeles:

Loyola High School of Los Angeles

In Honor of Michael P. O’Neil ‘56

1901 Venice Boulevard