William Krehm (November 23, 1913 – April 19, 2019) was a Canadian author, journalist, political activist and real estate developer.
He was a prominent Trotskyist activist in the 1930s and went to Spain where he participated in 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.