The carrier battle group (CVBG or CARBATGRU) or carrier strike group (CVSG) is a fleet of ships in support of an aircraft carrier. They are primarily used by the United States Navy which has 12 carrier battle groups scattered across the world. Their existence is an important part of the power projection capability of the United States in that they provide the ability to strike quickly almost anywhere in the world.

The large number of CVBGs used by the United States reflects in part a division of labor during the Cold War, in which the United States assumed primary responsibility for blue water operations and for safeguarding supply lines between the United States and Europe, while the NATO allies assumed responsibility for brown water and green water operations.

The need for a battle group is due to the fact that while the aircraft carrier has the ability to project a large amount of air power, it is vulnerable to attack from other surface ships and submarines. One way of looking at the CVBG is that the carrier performs the mission assigned to it while the primary role of the other ships is to protect the carrier.

CVBGs have no definitive specification and are formed and dissolved on an as-needed basis, and one may be different from another. However, they all are comprised of similar types of ships, and a typical carrier battle group might have:

• a carrier, usually Nimitz-class — The carrier provides a wide range of options to the U.S. government, ranging from simply showing the flag, to attacks on airborne, afloat and ashore targets. Because carriers operate in international waters, their aircraft do not need to secure landing rights on foreign soil. These ships also engage in sustained operations in support of other forces.
• two guided missile cruisers, usually Ticonderoga class — multi-mission surface combatants. Equipped with Tomahawk missiles for long-range strike capability.
• a guided missile destroyer, usually Arleigh Burke-class — multi-mission surface combatant, used primarily for anti-air warfare (AAW)
• a destroyer, usually Spruance-class — primarily for anti-submarine warfare (ASW)
• a frigate, usually Oliver Hazard Perry-class — primarily for anti-submarine warfare (ASW)
• two attack submarines, usually Los Angeles-class — in a direct support role seeking out and destroying hostile surface ships and submarines
• a combined ammunition, oiler, and supply ship , usually Sacramento or Supply class — provides logistic support enabling the Navy's forward presence: on station, ready to respond

The Carrier Battle Group (CVBG) could be employed in a variety of roles, most of which would involve the gaining and maintenance of sea control:

• Protection of economic and/or military shipping.
• Protection of a Marine amphibious force while enroute to, and upon arrival in, an amphibious objective area.
• Establishing air superiority or supremacy in an area in combination with land-based aircraft.
• Establishing a naval presence in support of national interests.

The CVBG was first used in World War II, primarily in conflicts between the United States and Japan in the Pacific. CVBGs at the time consisted of a far larger number of ships than current CVBGs, and this marked the only time CVBGs have fought each other, notably at the Battle of Midway.

During the Cold War, the main role of the CVBG in case of conflict with the Soviet Union would have been to protect Atlantic supply routes between the United States and Europe. Because the Soviet Union lacked its own carriers, a situation of duelling aircraft carriers would have been unlikely. The main scenario of interest would have been an attack against a CVBG using large number of anti-ship cruise missiles. The attempted use of anti-ship missiles against a carrier group was part of Argentina's efforts against Britain in the Falklands War.

In the late 20th and early 21st centuries, most of the uses of CVBGs by United States have been in situations in which their use has been uncontested. The main scenario involving carriers coming under fire which is of interest to naval strategists has been a conflict between the United States and the People's Republic of China over Taiwan. There is a consensus among observers that most of the military effort expended by the People's Liberation Army since the 1990s has been to at least complicate the deployment of a CVBG in a Taiwan straits conflict .

There is debate in naval warfare circles as to the viability of carrier battle groups in 21st century naval warfare. Proponents of the CVBG argue that it provides unmatched fire power and force projection capabilities. Opponents argue that CVBGs are increasingly vulnerable to cruise missiles and arsenal ships, were designed for Cold War scenarios, and are less useful in establishing control of areas close to shore.