The People's Liberation Army Navy Submarine Force (PLANSF) is the submarine service of the People's Liberation Army Navy. It consists of all types of submarines in operational service organized into three fleets: the North Sea Fleet, the East Sea Fleet, and the South Sea Fleet. Submarines have long been one of the three focuses of the People's Liberation Army Navy, and when the decision was made in late 2006 to concentrate on building other principal surface combatants to strengthen the air defense and to further delay the construction of aircraft carriers due to insufficient air cover, submarines will continue to play the lead dominant role in the assault force for the PLAN. Currently, PLANSF operates a fleet of 66 submarines which include nuclear as well as conventional submarines.

The People's Liberation Army Navy, also known as the People's Navy, PLA Navy or simply Chinese Navy, is the naval warfare branch of the People's Liberation Army, the standing armed force of the People's Republic of China. As of 2024, it is the second-largest navy in the world in terms of total displacement, and the largest navy per number of ships in active service.