Knox United Church, Gothic Revival church building in downtown Calgary, Canada

Knox United Church is a Gothic Revival church at Fourth Street and Sixth Avenue South in downtown Calgary, built in 1912–13 to designs by Lawson & Fordyce of Calgary in consultation with Allen & Collens of Boston. It is a stone construction, described as one of the most sophisticated examples of Gothic Revival architecture in western Canada.

The congregation was founded in 1883 and constructed the current building between 1912 and 1913 based on designs from local and Boston architects. This period marked a time of growth for Calgary, when the city needed new religious structures.

Knox became an affirming congregation in March 2007 after a vote at its annual meeting, committing to the full inclusion of gay, lesbian and transgender people. A permanent labyrinth opened in 2005 and is used for daily meditation. The church also hosts musical concerts of many kinds and works with Calgary's arts community.

The building is open to visitors on weekdays with staff available at specific times to provide assistance and answer questions. Plan enough time for a leisurely walk through the interior to appreciate the windows and architectural features.

Knox houses one of the largest Casavant Frères organs in western Canada, the centre of an active music programme. A permanent labyrinth opened in 2005 and is used for daily meditation. In March 2007 the congregation voted to become an affirming congregation, working for the full inclusion of gay, lesbian and transgender people.