The Baltimore-class heavy cruisers were a class of heavy cruisers in the United States Navy commissioned during and shortly after World War II. Fourteen Baltimores were completed, more than any other class of heavy cruiser, along with another three ships of the Oregon City sub-class. The Baltimores also were the first cruisers in the US Navy to be designed without the limitations of the London Naval Treaty.

A heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in calibre, whose design parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930. Heavy cruisers were generally larger, more heavily-armed and more heavily-armoured than light cruisers while being smaller, faster, and more lightly-armed and armoured than battlecruisers and battleships. Heavy cruisers were assigned a variety of roles ranging from commerce raiding to serving as 'cruiser-killers,' i.e. hunting and destroying similarly-sized ships