The Type 65 torpedoes are very large Cold War era torpedoes of Soviet origin. Due to their size the use of these weapon was limited to only a very few types of submarines. The Type 65 is one of the most capable anti-ship torpedoes in existence as it has a very high speed, a very long range and a very powerful payload. The Type 65 is also a very dangerous weapon system that needs to be handled with care due to its hydrogen peroxide fuel. A Type 65 torpedo has been blamed for the explosion that sunk the Russian Kursk nuclear powered missile submarine.

The Type 65 may have started out as an upscaled Type 53-65K torpedo. The Type 65 has a diameter of 650mm. The seeker is in the nose with the warhead directly behind it. The fuel and turbine engine make up most of the center. Unusually the guidance section is in the rear. The two contrarotating propellers are encased by control planes.

The anti-ship versions use acoustic wake homing. Inertial navigation by means of gyroscopes is used to guide the weapon to a position where the wake can be picked up. The nuclear variant uses inertial navigation towards a predefined detonation area.

The conventional Type 65 torpedoes carry a warhead of at least 450 kg, making it powerful enough to sink an aircraft carrier with only one torpedo. The warhead has both impact and proximity fuses. The nuclear variant may carry a more powerful warhead than the 20 kT range that is used in nuclear tipped 533mm torpedoes as more space and payload available.

Type 65 torpedoes are solely used on Russian submarines. Most SSN and SSBN designs since 1972 feature 650mm torpedo tubes, next to 533mm torpedo tubes. Use on surface ships and coastal defense launchers has been proposed for the export models.

The Type 65 torpedo is only used by Russia, although it has been offered for export. The accident with the Kursk led all Type 65's to be stored. There are reports that China adopted Type 65 technology, but 650mm torpedoes are currently not in use with the Chinese navy.