John Jennings Jr. (June 6, 1880 – February 27, 1956) was an American Republican, and a U.S. Representative from Tennessee from 1939 to 1951.

In 1918 he became special assistant to the Attorney General of the United States and judge of the second chancery division of Tennessee.

He resigned the judgeship on July 1, 1923, and moved to Knoxville, Tennessee, where he continued the practice of law.

In 1950, Howard Baker Sr. defeated him in his bid for renomination, so he ended his Congressional service on January 3, 1951.

Jennings died in Knoxville on February 27, 1956, and is interred at Highland Memorial Cemetery.