| Maitland Stewart McCarthy | |
| Constituency Mp: | Calgary |
| Parliament: | Canadian |
| Predecessor: | New District |
| Successor: | R. B. Bennett |
| Term Start: | November 3, 1904 |
| Term End: | September 20, 1911 |
| Office1: | Justice of the Supreme Court of Alberta |
| Term Start1: | July 11, 1914 |
| Term End1: | May 3, 1926 |
| Birth Date: | 5 February 1872 |
| Birth Place: | Orangeville, Ontario, Canada |
| Death Place: | Montreal, Quebec, Canada |
| Party: | Conservative |
| Alma Mater: | Trinity College |
Maitland Stewart McCarthy (February 5, 1872 - May 17, 1930) was a politician, lawyer and judge from western Canada.
Born in Orangeville, Ontario, he was the son of Thomas Anthony Maitland McCarthy, a county court judge, and Jennie Frances Stewart. He studied at Trinity College School in Port Hope and Trinity University, receiving a LLB in 1896. He was called to the Ontario bar in 1897 and set up practice in Sarnia.
In 1900, he married Eva Florence Watson. McCarthy moved to Calgary, then part of the Northwest Territories, in 1903. He was admitted to the bar and set up practice in Calgary with William L. Walsh.
Maitland was elected Calgary's first direct member of the House of Commons of Canada after the redistribution prior to the 1904 federal election gave Calgary its first direct seat. He was re-elected to a second term in the 1908 Canadian federal election.
Maitland was offered leadership of the provincial Conservative Party prior to the 1909 Alberta general election, but declined the offer of leadership as he would have to resign his federal seat which he won in a controversial election in 1908, and felt the resignation would be seen as an admission of guilt.
After leaving politics, he returned to the practice of law. McCarthy was named King's Counsel in 1913 and, in 1914, he was appointed to the Supreme Court of Alberta. In 1926, he retired from the bench due to health problems.
McCarthy died while on vacation in Montreal in 1930, aged 58.