Leon Jastremski (July 17, 1843 – November 29, 1907) was a French-born Confederate States Army soldier, journalist, and the three-term mayor of the Baton Rouge, Louisiana.

His father, Vincent Jastremski, was a Polish Jewish emigre, where he had studied medicine and married before moving with his family to Louisiana.

During the Civil War, he served as a private in the 10th Louisiana Infantry Regiment and for a time was with Col. Walerian Sułakowski's brigade in Virginia.

Jastremski elected chairman of the Democratic State Central Committee, and led Grover Cleveland's presidential campaign in Louisiana.

Historian Donald Everett noted that Jastremski, despite his place in important leadership roles, never "received more than superficial attention".

In his biography Pills, Pens, & Politics, Edward Pinkowski found numerous Polish immigrants in Baton Rouge existed during his time, but there is no convincing proof that he was friends with them or took a paternalistic attitude towards them as mayor.