Soviet submarine K-56 may refer to one of the following submarines of the Soviet Navy:
- Soviet submarine K-56 (1940), a K-class submarine; completed after World War II; sunk in nuclear tests in 1957
- Soviet submarine K-56 (1965), an Echo II-class (or Project 675) nuclear submarine; collided with merchant ship in June 1973, killing 27 men aboard
This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.