The Brooklyn-class cruiser was a class of nine light cruisers built for the United States Navy between 1935 and 1938. Armed with five triple 6-inch (152 mm) gun turrets, they mounted more main battery guns than any other standard US cruiser. The Brooklyn-class ships were all commissioned between 1937 and 1939, in the time between the start of the Second Sino-Japanese War and before the invasion of Poland. They served extensively in both the Pacific and Atlantic theaters during World War II.

A light cruiser is a type of small or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck. Prior to this smaller cruisers had been of the protected cruiser model, possessing armored decks only. While lighter and smaller than other contemporary ships they were still true cruisers, retaining the extended radius of action and self-sufficiency to act independently around the world. Cruisers mounting larger guns and heavier armor relative to most light cruisers would come to be known as heavy cruisers, though the designation of 'light' versus 'heavy' cruisers would vary somewhat between navies. Through their history light cruisers served in a variety of roles, primarily as convoy escorts and destroyer command ships, but also as scouts and fleet support vessels for battle fleets.