William Lees (November 21, 1821 – February 3, 1903) was an Ontario farmer, merchant and political figure.

[1] Lees was born in Bathurst Township, Lanark County, Upper Canada in 1821, the son of Scottish immigrants.

When his second wife died, Lees married school teacher Annie Irvine Laurie in 1868.

[2] [3] Lees fourth and final wife was Staffordshire-born Elizabeth Harriet Curtis née Smith, whom he married in 1886.

His youngest son, Frederick William, served as a lieutenant colonel during World War II.