William Frederick Waldow (August 26, 1882 – April 16, 1930) was a United States representative from New York.

Born in Buffalo, he attended the common schools, apprenticed as a plumber, and later engaged as a plumbing contractor.

He was unsuccessful for reelection in 1918 to the Sixty-sixth Congress and resumed former business pursuits.

He was a delegate to the Republican National Convention in 1920 and was sheriff of Erie County from 1921 to 1923.

He died in Snyder (a suburb of Buffalo) in 1930; interment was in Forest Lawn Cemetery.