Harry A. Estep was born in Pittsburgh, Pennsylvania.

He graduated from the University of Pittsburgh School of Law in 1913.

He served as assistant district attorney of Allegheny County, Pennsylvania, from 1917 to 1927.

Estep was elected as a Republican to the Seventieth, Seventy-first, and Seventy-second Congresses.

He died in Oakland, Pennsylvania, and is buried in Allegheny Cemetery.