Mary Silverthorn appointed President and CEO of Orillia Soldiers’ Memorial Hospital

(Orillia, ON) –   Terri McKinnon, Chair of Orillia Soldiers’ Memorial Hospital (OSMH) today announced the appointment of Mary Silverthorn as President and Chief Executive Officer (CEO) effective Tuesday, September 8, 2026.

Currently a Vice-President at Muskoka Algonquin Healthcare (MAHC), Silverthorn has deep ties to the local community and to the hospital, having served as OSMH Board Chair nearly 20 years ago alongside an extensive senior leadership career at OPP headquarters in Orillia.

“To be entrusted to lead this hospital in my hometown community that I hold so dear is both a privilege and a profound responsibility that is incredibly meaningful to me,” said Silverthorn.

“As evidenced by their Exemplary Standing award from Accreditation Canada just two months ago, and back-to-back international surgical quality awards, OSMH has earned a strong reputation for providing high-quality, compassionate care.  I look forward to working alongside the dedicated team in place to build on that foundation, guided by the organization’s values of teamwork, trust, accountability, integrity, and humility.”

Silverthorn has the rare distinction of serving both as a past governor of the hospital and as a former team member, including a dual role spanning OSMH and MAHC as Integrated Vice-President, Human Resources.

In addition to her healthcare background, Silverthorn served 11 years as a senior executive with the Ontario Provincial Police (OPP) as the Provincial Commander of Corporate Services Command. In this role, she oversaw human resources, finance, training, and operational areas, managing over 550 personnel.

“Mary’s leadership credentials are exceptionally well aligned with OSMH’s future priorities,” said McKinnon, noting her appointment comes at a pivotal time as OSMH continues to advance plans for a new hospital and expand services to meet the evolving needs of the communities it serves.

“Mary has led complex transformational initiatives, overseen budgets exceeding $1 billion, and successfully advanced major redevelopment projects. Her experience navigating government, funding, and stakeholder environments positions her to lead OSMH with confidence through its redevelopment journey and continued growth.”

Recognized for her integrity, authenticity, and commitment to service, she is a strategic, values-driven leader with the vision, experience, and leadership presence required to guide OSMH through its next chapter and deliver on its aspiration of building a healthier, more integrated future for the communities it serves.

Silverthorn succeeds Carmine Stumpo, who stepped down from the role on April 2, 2026, to assume a similar position with Mackenzie Health. Tom Roberts will continue to serve as Interim President and CEO until her arrival in September.

Mary Silverthorn, Appointed OSMH President and CEO (effective September 8, 2026)

Additional background for Mary Silverthorn

• Masters of Business Administration from the University of Ottawa
• Certificate of Law from Queen’s University
• Certified Human Resources Executive (CHRE) through the Human Resources Professionals Association.
• Officer of the Order of Merit of the Police Forces
• Recipient of the Queen Elizabeth II Diamond Jubilee Medal for her contributions to policing
• Provincial Commander (Assistant Deputy Minister), Corporate Services Command, Ontario Provincial Police (2012 – 2023)
• Bureau Commander (Director), Career Development Bureau, Ontario Provincial Police (2009 – 2012)