USS John C. Stennis, a typical supercarrier, and HMS Illustrious, a light V/STOL aircraft carrier on a joint patrol. The Stennis is much larger in every dimension.

A supercarrier is a word sometimes used to describe a form of aircraft carrier, with no official meaning. It is generally considered to be 75,000 tons or greater in displacement — most countries operate carriers with a displacement of less than 40,000 tons (such as Charles de Gaulle), and more often closer to 15,000 (such as HMS Illustrious.)

The 81,000 ton USS Forrestal was the first operational supercarrier, though United States would have been in service earlier, had it been completed; its cancellation triggered the "Revolt of the Admirals." United States would have had a nuclear strategic bombing role, rather than the multipurpose role that all subsequent supercarriers have had, carrying tactical aircraft only for defense. The 72,000 ton armored Japanese carrier Shinano of the World War II era was almost heavy enough to be considered a supercarrier, but lacked several defining features, such as catapults, arrestor cables, and angled flight decks, and also did not possess the sheer size of modern supercarriers. Because of the angled deck and large deck area, supercarriers can have a far larger island than conventional carriers, greatly improving both their aviation capabilities and their capability as flagships.

The U.S. Navy is now the only major sea power building large aircraft carriers, of which the 100,000 ton Nimitz class is the most prolific. All completed supercarriers are American, although the Soviet Union did begin construction of Ulyanovsk, an 85,000 ton nuclear carrier comparable in size to earlier American supercarriers. Ulyanovsk was 40% complete when cancelled (along with a follow-on vessel) after the end of the Cold War in 1991.

Supercarrier classes

• United States (USA, 1950s) - Single-unit class, cancelled
• Forrestal class (USA, 1955) - Four unit class, all decommissioned
• Kitty Hawk class (USA, 1961) - Three unit class, two decommissioned, one active
• Enterprise (USA, 1961) - Single-unit class, still active
• John F. Kennedy (USA, 1968) - Single-unit class, a modified Kitty Hawk design, still active
• Nimitz class (USA, 1975) - Final unit (of ten) scheduled for completion in 2009, all units still active
• Ulyanovsk (USSR, 1990s) - Two units cancelled after partial completion
• CVN-21 (USA, 2013) - Two units pending