The M551 "Sheridan" AR/AAV was a light tank developed by the U.S. and named after American Civil War hero General Philip Sheridan. It was designed to be air-dropped and amphibious. It was equipped with the innovative but problematic 152 mm M81 tank gun, which could fire both conventional ammunition and the MGM-51 Shillelagh anti-tank guided missile (ATGM). Despite the use of advanced technologies for its time, the performance of the vehicle was lackluster and below expectations. It saw extensive combat in the Vietnam War, where its shortcomings became evident, especially its low survivability and reliability. It was later used in the National Training Centre as a simulated Soviet armoured opposition force (OPFOR) to train US military units on simulated tank-on-tank armoured combat in a desert environment. The last Sheridans were retired from the NTC in 2003.

Introduced in Update 1.59 "Flaming Arrows", the M551 "Sheridan" AR/AAV is a very unorthodox vehicle at its BR. With a stock 152mm HE and HEAT shell on a low velocity, high shell drop gun, the Sheridan initially has limited engagement range and effectiveness. The MGM-51 Shillelagh ATGM is a significant improvement over conventional rounds, capable of destroying almost anything with a single penetration and greatly extends the engagement range of the Sheridan to a max of over 3 kilometers. Players should still be cautious of enemy vehicles due to the Sheridan's weak armour, and use cover as much as possible to ensure their survival.