The UGM-96 Trident I, or Trident C4, was an American submarine-launched ballistic missile (SLBM), built by Lockheed Martin Space Systems in Sunnyvale, California.

[2] The missile was a three-stage, solid-fuelled system, capable of carrying up to eight W76 warheads in the Mark 4 RB.

Twelve James Madison- and Benjamin Franklin-class submarines were also retrofitted with Trident I missiles, which replaced older Poseidon missiles.

In 1980, the Royal Navy requested Trident I missiles under the Polaris Sales Agreement.

In 1982, the agreement was changed to supply Trident II instead.