Oscar Lawrence Jackson (September 2, 1840 – February 16, 1920) was a Republican member of the U.S. House of Representatives from Pennsylvania and the commander of an Ohio infantry regiment in the Union Army during the American Civil War.

He was shot in the face by a Confederate soldier with a Squirrel Rifle and left for dead in the 2nd Battle of Corinth.

After the war, Jackson studied law, was admitted to the bar in 1867 and commenced practice in New Castle, Pennsylvania.

He was a member of the commission to codify laws and devise a plan for the government of cities of Pennsylvania in 1877 and 1878.

He published a book The fiery trail : a Union officer's account of Sherman's last campaigns Jackson was elected as a Republican to the Forty-ninth and Fiftieth Congresses.