A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from some submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs) each of which carries a nuclear warhead and allows a single launched missile to strike several targets. Submarine-launched ballistic missiles operate in a different way to submarine-launched cruise missiles.

The first practical design of a submarine-based launch platform was developed by the Germans near the end of World War II involving a launch tube which contained a ballistic missile and was towed behind a submarine. The war ended before it could be tested, but the engineers who had worked on it went on to work for the USA and USSR on their SLBM programs. These and other early SLBM systems required vessels to be surfaced when they fired missiles, but launch systems eventually were adapted to allow underwater launching in the 1950-1960s. The United States made the first successful underwater launch of a Polaris A1 on 20 July 1960. Forty days later, the Soviet Union made its first successful underwater launch of a submarine ballistic missile in the White Sea on 10 September 1960 from the same converted Project 611 (Zulu Class) submarine that first launched the R-11FM (SS-N-1 Scud-A, naval modification of SS-1 Scud) on 16 September 1955. However, the Soviet Union was able to beat the U.S. in launching and testing the first armed SLBM, an R-13 that detonated in the Novaya Zemlya Test Range in the Arctic Ocean, doing so on October 20, 1961.