Glendale High School is located in Tillsonburg, Ontario, Canada, and was founded in 1959. We are a fully composite school community offering courses for students in grades 9 through 12, along with sports, clubs and special events.

Students within the attendance boundary live in Tillsonburg, Otterville, Straffordville, Springford, Brownsville, and Courtland.

We are the Gemini, our mascot is the Griffin and the school colours are black, gold, white, and green.

The school underwent renovations in 2010 and saw the addition of a new west wing which consisted of a new gymnasium and greenhouse, along with new Science, History, Geography, Law, Horticulture, Dance and French classrooms.  In 2012 another addition was added for a weight room.