Jack O'Donnell

Jack O’Donnell

CEO and Board Member

Jack O’Donnell is a successful entrepreneur and business leader, with over 40 years experience leading organizations. While Jack’s background is diverse, including operating large businesses in the hospitality industry, he has dedicated the past 15 years of his career to the addiction and behavioral health field. With experience operating throughout the United States and Europe, Jack is perfectly suited to direct C4’s diverse activities worldwide.

Jack was the CEO of Sierra Tucson, directing both growth and exit strategies for the company during its later years, under its original ownership. He has also, along with his wife Nancy, developed and successfully opened a treatment facility specializing in trauma and addiction issues. Additionally, Jack has consulted with private equity firms and investors, assisting in acquisition, exit, and business development activities.

Outside of work, Jack maintains a balanced life. A long time ultra endurance athlete and climber, he is also a proud horseman, still competing nationally in reining events. He is a board member of the Lacey Jarrell Foundation, a non-profit, which supports passionate young artists. The organization is named in honor of his wife Nancy’s daughter, Lacey. Jack has also written a book about his professional career, which was published by Simon and Schuster.