Isaac Riley (October 1853—July 8, 1926) was a politician in Manitoba, Canada. He served in the Legislative Assembly of Manitoba from 1899 to 1915 as a member of the Conservative Party.Riley was born in Mornington Township in Perth County, Canada West (now Ontario), the son of Charles Riley, and was educated at public schools. He entered business as a lumber merchant. In 1876, Riley came to Winnipeg. He later moved to Stonewall, Manitoba where he was a lumber merchant and also owned a hotel.