The 1911 Oldham by-election was a Parliamentary by-election held on 13 November 1911. The constituency returned two Members of Parliament (MP) to the House of Commons of the United Kingdom, elected by the first past the post voting system.

Oldham was a parliamentary constituency centred on the town of Oldham, England. It returned two Members of Parliament (MPs) to the House of Commons of the Parliament of the United Kingdom. The constituency was created by the Great Reform Act of 1832 and was abolished for the 1950 general election when it was split into the Oldham East and Oldham West constituencies.