Jacob Bowman Sweitzer (July 4, 1821 – November 9, 1888) was a Pennsylvania lawyer and soldier who commanded a regiment and then a brigade in the Army of the Potomac in the American Civil War.

He and his men were significantly engaged at the 1863 Battle of Gettysburg, where they reinforced and helped temporarily stabilize the Union defensive line on the second day of fighting.

His Paternal ancestors were George Ludwig "Lewis" Sweitzer 1740-1795, and Conrad Sweitzer/Schweitzer 1706-1770, who arrived in Philadelphia in 1749, from Germany.

He later studied law, passed the bar exam, and established a legal practice in Pittsburgh, Pennsylvania.

In 1849, he was nominated as U.S. Attorney for the Western District of Pennsylvania by President Zachary Taylor to succeed John L. Dawson.

After being exchanged on August 15, 1862, he led his regiment in the First Division, V Corps at the Second Battle of Bull Run and at Antietam in the brigade of Brig.

Col. Harrison Jeffords of the 4th Michigan Infantry was killed when Confederate soldiers tried to capture his regiment’s flag.

When the Army of the Potomac was reorganized preceding Lt. Gen. Ulysses S. Grant's Overland Campaign, Sweitzer retained brigade command in Griffin’s First Division.

Sweitzer distinguished himself at the Battle of North Anna, holding the exposed right flank of V Corps during a Confederate attack near Jericho Mills.