S.O.S. (セプテントリオン, Seputentorion, Septentrion) is a survival adventure developed by Human Entertainment and published by Vic Tokai for the Super Nintendo Entertainment System (SNES). It was originally released in Japan on May 28, 1993, and later in North America in April of 1994.

Mostly based on the 1969 book and 1972 film, The Poseidon Adventure, the game is set on September 13, 1921, and the players must escape the sinking ship Lady Crithania, which is hit by a gigantic wave and capsizes off the coast of Humbleton, England.

The player must escape from the ship within a one-hour time limit. The timer is hidden except when the player injures themselves, in which case they fall unconscious and lose five minutes of time. After a period of time, the ship begins to periodically tilt in the water and gradually fill with water.

Depending on how many survivors the player finds, who they are and how valuable they are to the character player selected, the ending will vary. The best ending for each character is obtained by escaping the boiler room, the final area of the game.

A follow up title, Septentrion: Out of the Blue, released only in Japan for the PlayStation.

The soundtrack was composed by Kouji Niikura, Hiroyuki Naka, and Hiroshi Taniguchi.