Thomas Alexander Crerar PC CC (17 June 1876 – 11 April 1975) was a western Canadian politician and a leader of the short-lived Progressive Party of Canada.

Although he had no experience as an elected official, he was appointed as Minister of Agriculture in Robert Laird Borden's Union government on October 12, 1917, to provide a show of national unity during the First World War.

In the 1921 election, he led the party to a landslide victory in western Canada, giving them 65 seats in the House of Commons.

Crerar spent some time in the private sector before returning to politics in 1929, as a member of William Lyon Mackenzie King's Liberal Party.

Although once again not holding a seat in parliament, he was appointed Minister of Railways and Canals (Canada) on December 30, 1929, and won a by-election in Brandon on February 5, 1930.