Todmorden Mills was a small settlement located in the Don River valley in Toronto, Ontario. It started out as a lumber mill in the 1790s. Originally known as "Don Mills", it grew into a small industrial complex and village before becoming part of East York in the 20th century. Currently the valley site is occupied by the Todmorden Mills Heritage Museum and Arts Centre, which includes the museum, art gallery, a theatre and a forest preserve.
In 1795, the settlement of York in Upper Canada was a small but growing community on the shores of Lake Ontario. In order to supply construction material, Lieutenant-Governor John Graves Simcoe granted land on the Don River to Aaron and Isaiah Skinner for the purpose of building a mill to supply lumber. Simcoe wrote to a friend "A mill should be build (sic) thereon". The mill was operated by the Skinners until about 1855 when it was sold to the Taylor family. In 1820 a brewery was built next to the mill and operated by Thomas Helliwell and John Eastwood. The Helliwell family operated it until 1855 when it too was sold to the Taylor family. Todmorden Mills acquired its name from John Eastwood, one of the original brewery owners. His family had emigrated from Todmorden, a town then straddling the two counties of Lancashire and Yorkshire in England.
The Taylors owned a number of industrial mills in the neighbourhood including the Don Valley Brick Works. Under their ownership the mill was converted to produce felt paper. The mill continued to operate until the 1920s when the building was converted into a riding stable.
In the early 1940s, the site became the location of a small German prisoner of war camp. The camp housed men from the German merchant marine who were interned in Allied ports at the start of the war. The prisoners often worked as labourers at the nearby Don Valley Brick Works. In 1945, the prisoners were repatriated and the camp was shut down. Soon afterwards, the camp buildings were destroyed by fire, likely set by vandals.