Frederick Simpson Deitrick (April 9, 1875 – May 24, 1948) was a U.S. Representative from Massachusetts.

Born in New Brighton, Pennsylvania, Deitrick attended the public schools.

He graduated from Geneva College, Beaver Falls, Pennsylvania, in 1895 and from Harvard Law School in 1898.

He died in Middleton on May 24, 1948, and was interred in Cambridge at Mount Auburn Cemetery.

This article incorporates public domain material from the Biographical Directory of the United States Congress