Woodstock Collegiate Institute is a school in Woodstock, Ontario, Canada. It is part of the Thames Valley District School Board.

The school was founded in 1841 by an Act of Parliament as Woodstock's first grammar school. Its growth forced a series of physical moves; the school relocated in 1851, 1881, and to its present site in 1939.

The school faced possible closing at the end of the 20th century. It underwent major faculty improvements, including renovating science classrooms, that were completed in 2001.

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