The 503rd Heavy Panzer Battalion (; abbreviated: "s.Pz.Abt. 503") was a German heavy Panzer "Abteilung" (independent battalion-sized unit) equipped with Tiger I and Panzer III tanks. In 1944, it was re-equipped with the new Tiger II. The battalion saw action on the Eastern and Western Fronts during World War II. As with other German heavy tank battalions, it was normally not assigned to a single corps, but shuffled around according to war circumstances. Later the battalion became part of the newly formed Panzer Corps Feldherrnhalle as the Feldherrnhalle Heavy Tank Battalion.