Maitland Stewart McCarthy KC (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 was admitted to the bar and set up practice in Calgary with William L. Walsh.

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.

McCarthy was named King's Counsel in 1913 and, in 1914, he was appointed to the Supreme Court of Alberta.