USS Triton (SSRN/SSN-586), the only member of her class, was a nuclear powered radar picket submarine in the United States Navy. She had the distinction of being the only Western submarine powered by two nuclear reactors. Triton was the second submarine and the fourth vessel of the United States Navy to be named for the Greek god Triton. At the time of her commissioning in 1959, Triton was the largest, most powerful, and most expensive submarine ever built at $109 million excluding the cost of nuclear fuel and reactors.