The Canada Southern Railway, also known as CSR, was a railway in southwestern Ontario, Canada, founded on February 28, 1868 as the Erie and Niagara Extension Railway. Its name was changed to Canada Southern Railway on December 24, 1869. The 1868 Act specified that it was to be constructed at a broad gauge of 5 ft 6 in, but that requirement was repealed in the 1869 Act, thus allowing construction at the standard gauge of 4 ft 8+1⁄2 in.
Share of the Canada Southern Railway Company, issued 8 January 1912.