Gordon Graydon Memorial Secondary School

Gordon Graydon Memorial Secondary School, "Gordon Graydon", "GGMSS", or simply "Graydon" for short, was a high school that served Grades 9 to 12 in Mississauga, Ontario, Canada. The school opened in 1957, and celebrated its 50th anniversary on May 26, 2007. It was named after Gordon Graydon, a Canadian politician who died in 1953. The school's slogan was "Palma Per Ardua": "Success through Hard Work".

Gordon Graydon was home to the International Business and Technology Program, the Graphic and Design Management Program, and the Specialist High Skills Major Program. The school was home of the only Graphic Design and Management Program in Ontario.