David and Mary Thomson Collegiate Institute (sometimes called David and Mary Thomson, DMT, DMTCI, Thomson CI or Thomson) is a semestered English-language high school in Toronto, Ontario, Canada. Located in the Bendale neighbourhood of the district of Scarborough. It was originally sanctioned by the Scarborough Board of Education and since 1998 under its successor board, the Toronto District School Board.

From 1959–60 until the 2018–19 school year, Thomson was housed in the Lawrence Avenue East building constructed in 1958 and the new school building was built in the former Bendale Business and Technical Institute property in 2019. The school was named after David and Mary Thomson, the first European settlers who immigrated to Scarborough in the late 18th century. Its motto is Nil Sine Magno Labore ("Nothing worthwhile is accomplished without hard work").