The 155th Pennsylvania Volunteer Infantry Regiment was a federal infantry regiment that served in the American Civil War. During their first years the regiment wore the regulation uniform of the Union Army, but in 1863 they along with the 140th New York received Zouave uniforms. Unlike the 140th New York, the 155th Pennsylvania received a Zouave uniform never before created. Their uniform consisted of a dark blue Zouave jacket with not red but yellow trimming, a dark blue Zouave vest with yellow trimming, a red Zouave sash with a yellow trimming, dark blue Zouave pantaloons, and a red Zouave fez with a yellow trimming and a blue tazzle. The 155th Pennsylvania along with the 140th New York, and the 146th New York became the "Zouave Brigade" in the Army of the Potomac.