William Harold Clark (July 1, 1869 – December 24, 1913) was an English-born Canadian businessman and politician.

After being educated in London's public schools, he went to work for his father at age sixteen in the building and contracting business.

In Edmonton, he founded W. H. Clark & Company, which produced sash, doors, and interior furnishings.

Clark established the Edmonton Lumber Company in 1905, which logged on the North Saskatchewan River.

Clark was a director of the YMCA, and a member of the Independent Order of Odd Fellows, the Sons of England, the Edmonton Club, and the Masonic Lodge.