The Avenger-class escort carrier was a class of escort carriers comprising three ships in service with the Royal Navy during the Second World War and one ship of the class in the United States Navy called the Charger Type of 1942-class escort carrier. All three were originally American type C3 merchant ships in the process of being built at the Sun Shipbuilding and Drydock Company Chester, Pennsylvania. The ships laid down in 1939 and 1940 were launched and delivered to the Royal Navy by 1942 under the Lend-Lease agreement.

The escort carrier or escort aircraft carrier, also called a "jeep carrier" or "baby flattop" in the United States Navy (USN) or "Woolworth Carrier" by the Royal Navy, was a small and slower type of aircraft carrier used by the Royal Navy, the Royal Canadian Navy, the United States Navy, the Imperial Japanese Navy and Imperial Japanese Army Air Force in World War II. They were typically half the length and a third the displacement of larger fleet carriers, more-lightly armed and armored, and carried fewer planes. Escort carriers were most often built upon a commercial ship hull, so they were cheaper and could be built quickly. This was their principal advantage as they could be completed in greater numbers as a stop-gap when fleet carriers were scarce. However, the lack of protection made escort carriers particularly vulnerable, and several were sunk with great loss of life. The light carrier was a similar concept to the escort carrier in most respects, but was fast enough to operate alongside fleet carriers.