The Order of Ontario is the province’s highest honour. It is reserved for Ontarians from all fields of endeavour and backgrounds, whose excellence has left a lasting legacy in the province, Canada and beyond. Members of the Order are a collective of Ontario’s finest citizens, whose contributions have shaped – and continue to shape – the province’s history and place in Canada.

Anyone can nominate a living a long-term or former resident of Ontario "whose career, in any field, has had a major impact or influence on the province, Canada or abroad."

An advisory council reviews the nominations and recommends candidates to the Lieutenant Governor for appointment to the Order of Ontario.
The council consists of the Chief Justice of Ontario, the Speaker of the Legislative Assembly, the Secretary of the Cabinet and up to six additional members of the Order of Ontario appointed to the council by the Premier.

Examples of appointees include:
Dr. Roberta Bondar, Canada’s first female astronaut and the world’s first neurologist in space
The Honourable George E. Carter, the first Canadian-born black judge in Canada, instrumental in establishing legal aid services in Ontario
David Cronenberg, an award-winning director, producer, filmmaker, screenwriter, actor and author
Jane Jacobs, an urban writer and activist who championed new, community-based approaches to planning for over 40 years
Arthur B. McDonald, an astrophysicist who co-won the 2015 Nobel Prize in Physics for discovering neutrino oscillations, which shows that neutrinos have mass
Ted Nolan, a former professional hockey player, former head coach of the Buffalo Sabres, and former head coach of Latvia’s national men’s ice hockey team. He established the Ted Nolan Foundation to support Indigenous youth and women across Canada
The Honourable Maryka Omatsu, Canada’s first female judge of East Asian ancestry. She was a member of the National Association of Japanese Canadians’ negotiation team in its quest for Canadian redress for the World War II internment
Rahul Singh, the founder of GlobalMedic, recognized on Time Magazine’s 2010 list of the world’s 100 most influential people for providing immediate catastrophic disaster relief using volunteer professional emergency workers

source: Ontario honours and awards