Bill Crothers Secondary School is an athletic based high school in the community of Unionville in Markham, Ontario, Canada. It was the newest secondary school in the York Region District School Board for a number of years, since 2008. Named for the former Olympic athlete and Chair of the York Region District School Board, Bill Crothers, the school opened its doors to Grade 9 and 10 students in August 2008. The school is 32 acres (130,000 m) and cost an estimated $32 million to build. The school was formerly an 18-hole golf course, Unionville Golf Centre, opened in 1961.

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• Andrew Coe, professional rugby player
• Carol Zhao, Chinese-Canadian tennis player
• Trae Bell-Haynes, basketball player
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• Anthony Cirelli, ice hockey player for the Tampa Bay Lightning
• Travis Dermott, ice hockey player for the Utah Hockey Club
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• Education in Ontario
• List of secondary schools in Ontario

• Official web site
• School Profile at the York Region District School Board
• Profile at the Education Quality and Accountability Office (EQAO) web site