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 (the British County class had 15 vessels planned, but only 13 completed), 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.

Fast and heavily armed, the Baltimore cruisers were mainly used in World War II as anti-aircraft cruisers to protect the fast aircraft carriers in battle groups from air attack. Additionally, their 8-inch (203 mm) main guns and secondary 5-inch (127 mm) guns were regularly used to bombard land targets in support of amphibious landings. After the war, only six Baltimores (St. Paul, Macon, Toledo, Columbus, Bremerton, and Helena) and two Oregon City-class ships (Albany and Rochester) remained in service, while the rest were moved to the reserve fleet. However, all ships except Boston, Canberra, Chicago, and Fall River were reactivated for the Korean War.

Except for St. Paul, all the ships retaining all-gun configurations had very short (18 years or less) service lives, and by 1971 were decommissioned, and started being sold for scrap. However, four Baltimore-class cruisers were refitted and converted into some of the first guided missile cruisers in the world, becoming two of the three Albany-class and two Boston-class cruisers. The last of these was decommissioned in 1980, with the Chicago lasting until 1991 in reserve. No example of the Baltimore class still exists.