The APS underwater assault rifle is an underwater firearm designed by the Soviet Union in the early 1970s. It was adopted in 1975. Made by the Tula Arms Plant in Russia, it is exported by Rosoboronexport.

An underwater firearm is a firearm designed for use underwater. Underwater firearms or needleguns usually fire flechettes or spear-like bolts instead of standard bullets. These may be fired by pressurised gas.