Michael Casey (September 21, 1860 – May 2, 1937) was an Irish-born American labor unionist and politician who served as San Francisco Commissioner of Public Works from 1902 to 1913.

Born in Elphin, County Roscommon, in Ireland, Casey emigrated with his family to the United States in 1871.

In 1900, he and John P. McLaughlin founded a local of the Team Drivers' International Union in the city.

The following year, he led the union through a major strike, during which he was nicknamed "Bloody Mike" by opponents, a title which he embraced.

[1] In 1903, the Team Drivers merged into the new International Brotherhood of Teamsters, which appointed Casey as its West Coast organizer.