The Lexington-class aircraft carriers were a pair of aircraft carriers built for the United States Navy (USN) during the 1920s, the USS Lexington (CV-2) and USS Saratoga (CV-3). The ships were built on hulls originally laid down as battlecruisers after World War I, but under the Washington Naval Treaty of 1922, all U.S. battleship and battlecruiser construction was cancelled. The Treaty, however, allowed two of the unfinished ships to be converted to carriers. They were the first operational aircraft carriers in the USN^{[N 1]} and were used to develop carrier aviation tactics and procedures before World War II in a series of annual exercises.

USS Lexington before World War II
Class overview
Name	Lexington class
Builders	Fore River Shipyard New York Shipbuilding Corporation
Operators	United States Navy
Preceded by	USS Langley (CV-1)
Succeeded by	USS Ranger (CV-4)
Cost	about $45,000,000
Built	1920–1927
In service	1927–1946
In commission	1927–1946
Planned	2
Completed	2
Lost	1
Retired	1
General characteristics (as built)
Type	Aircraft carrier
Displacement	36,000 long tons (37,000 t) (standard)
Length	888 ft (270.7 m) (oa)
Beam	106 ft (32.3 m)
Draft	30 ft 5 in (9.3 m) (deep load)
Installed power	16 water-tube boilers 180,000 shp (130,000 kW)
Propulsion	4 shafts 4 sets turbo-electric transmission
Speed	34.5 knots (63.9 km/h; 39.7 mph) (actual)
Range	10,000 nmi (19,000 km; 12,000 mi) at 10 knots (19 km/h; 12 mph)
Complement	2,791 (including aviation personnel), 1942
Armament	4 × twin 8 in (203 mm) guns 12 × single 5 in (127 mm) AA guns
Armor	Belt: 5–7 in (127–178 mm) Deck: 0.75–2 in (19–51 mm) Gun turrets: 0.75 in (19 mm) Bulkheads: 5–7 in (127–178 mm)
Aircraft carried	90
Aviation facilities	1 × Aircraft catapult 2 × Elevators

They proved extremely successful as carriers and experience with the Lexington class convinced the Navy of the value of large carriers. They were the largest aircraft carriers in the USN until the Midway-class aircraft carriers were completed beginning in 1945. The ships served in World War II, seeing action in many battles. Although Lexington was sunk in the first carrier battle in history (the Battle of the Coral Sea) in 1942, Saratoga served throughout the war, despite being torpedoed twice, notably participating in the Battle of the Eastern Solomons in mid-1942 where her aircraft sank the Japanese light carrier Ryūjō. She supported Allied operations in the Indian Ocean and South West Pacific Areas until she became a training ship at the end of 1944. Saratoga returned to combat to protect American forces during the Battle of Iwo Jima in early 1945, but was badly damaged by kamikazes. The continued growth in the size and weight of carrier aircraft made her obsolete by the end of the war. In mid-1946, the ship was purposefully sunk during nuclear weapon tests in Operation Crossroads.