Union Presbyterian Church is located north-east of the village on 22nd Sideroad , which becomes Old School Road at the Halton-Peel border. The pioneering farmers of Salmonville (now Terra Cotta) and Williamsburgh (now Glen Williams) formed a congregation in 1833 and opened this magnificent stone church in 1884.
A small but active congregation meets on Sundays and offers Sunday School for the children. They support many outreach and development efforts, and every year raise several thousand dollars for local charities such as the Georgetown Bread Basket, Cancer Assistance Services of Halton Hills, Bethel House and the Salvation Army.