Project Azorian was a U.S. Central Intelligence Agency (CIA) project to recover the sunken Soviet submarine K-129 from the Pacific Ocean floor in 1974 using the purpose-built ship Hughes Glomar Explorer. The 1968 sinking of K-129 occurred about 1,600 miles (2,600 km) northwest of Hawaii. Project Azorian was one of the most complex, expensive, and covert intelligence operations of the Cold War at a cost of about $800 million, or $4.9 billion today.

K-129 was a Project 629A diesel-electric-powered ballistic-missile submarine that served in the Pacific Fleet of the Soviet Navy–one of six Project 629 strategic ballistic-missile submarines assigned to the 15th Submarine Squadron based at Rybachiy Naval Base near Petropavlovsk, commanded by Rear Admiral Rudolf Golosov.