William Krehm (November 23, 1913 – April 19, 2019) was a Canadian author, journalist, political activist and real estate developer. He was born in Toronto. He was a known Trotskyist activist in the 1930s. He went to Spain where he was part of the Spanish Civil War. In the 1980s he co-founded the Committee on Monetary and Economic Reform (COMER) in the 1980s and continued as the group's principal leader until his death.