Б-37 (B-37) was a project 641 (NATO reporting name "Foxtrot" ) diesel submarine of the Soviet Navy's Northern Fleet.

On 11 January 1962, the submarine was tied up at the pier in Ekaterininsky , with all watertight doors open, while conducting maintenance and testing of her torpedoes. A fire broke out in the torpedo compartment, and all twelve torpedoes cooked off. The entire submarine was instantly lost with all hands except the commanding officer Captain Second Rank Begeba who was on the pier at the time of explosion, and Captain Third Rank Jakubenko, who was on another part of the sub base.

The project 633 ("Romeo") submarine С-350 , tied up next to Б-37, was badly damaged by the explosion as well, and several men from other ships and the shipyard were killed. In total, 122 men died as a result of the explosion.