A submarine aircraft carrier is a submarine equipped with aircraft for observation or attack missions. These submarines saw their most extensive use during World War II, although their operational significance remained rather small. The most famous of them were the Japanese I-400-class submarines and the French submarine Surcouf, although small numbers of similar craft were built for other nations' navies as well.

The I-400-class submarine Imperial Japanese Navy (IJN) submarines were the largest submarines of World War II and remained the largest ever built until the construction of nuclear ballistic missile submarines in the 1960s. The IJN called this type of submarine Sentoku type submarine . The type name was shortened to Toku-gata Sensuikan . They were submarine aircraft carriers able to carry three Aichi M6A Seiran aircraft underwater to their destinations. They were designed to surface, launch their planes, then quickly dive again before they were discovered. They also carried torpedoes for close-range combat.