Commodore Oscar Charles Badger (August 12, 1823 – June 20, 1899) was an officer of the United States Navy who served in the Mexican–American and American Civil Wars.

Badger received an appointment as a midshipman in the United States Navy on September 9, 1841, and, after a tour of duty in the Independence, served in Saratoga along the Atlantic coast of Africa.

In 1855, he returned to the Pacific Squadron for duty in the sloop John Adams and, that autumn, participated in an expedition to the Fiji Islands to redress wrongs suffered by members of the crews of American whalers and merchant ships at the hands of natives.

To round out his pre-Civil War service, Badger was assigned in turn to the Plymouth, Macedonian, Minnesota, and, lastly, to the Washington Navy Yard.

[2] Soon thereafter, Badger was appointed fleet captain, ad interim, of the South Atlantic Blockading Squadron and, in that office, took part in another attack on Fort Sumter while in the flagship Weehawken on the night of September 1, 1863.

[1] He spent the remaining years of the Civil War ashore performing ordnance duty at the Philadelphia Navy Yard and serving as inspector of cannon at Pittsburgh, Pennsylvania.

[2] On December 26, 1866, he took command of the newly commissioned sidewheel steamer USS Peoria—a ship of the North Atlantic Squadron—and, in her, rendered assistance to the victims of a fire that destroyed Basseterre on St. Kitts in the Leeward Islands.