Michael Copps Costello (August 2, 1875 – March 22, 1936) was a Canadian printer, a medical graduate (who never practiced his profession) and the 19th mayor of Calgary, Alberta, holding office from 1915 to 1919.

He then went to London, England for a year's post-graduate education and continued with further medical studies at the Rotunda Hospital in Dublin, Ireland.

Michael's father John William Costello was a trustee of the Separate School District of the Northwest Territories, and chairman of the board from 1899 to 1904 which would later become the Calgary Catholic School Board.

He ran unsuccessfully as a Conservative MLA candidate in the Calgary electoral riding in the 1921 and 1926 Alberta general elections.

Costello died in 1936, aged 60 and is buried in Saint Mary's Pioneer Cemetery in Calgary.