Pierre Leon (August 23, 1838 – December 7, 1915) was a Captain of the Forecastle in the Union Navy and a Medal of Honor recipient for his actions in the American Civil War.

He served on several coastal steamers until 1860, when he became involved in the development of the Alligator, an experimental submarine.

He served on no less than 8 different ships, including the USS Baron De Kalb, before his discharge exactly four years later.

Baron De Kalb, with the object of capturing or destroying the enemy's transports, came upon the steamers John Walsh, R. J. Locklan, Golden Age and the Scotland sunk on a bar where they were ordered fired.

Returning down the Yazoo, she destroyed and captured larger quantities of enemy equipment and several prisoners.