Battery Gadsden, Artillery battery at Sullivan's Island, South Carolina, US

Battery Gadsden is an artillery battery on Sullivan's Island that once served for coastal defense and now houses community and cultural facilities. The structure features substantial concrete walls and open spaces where visitors can walk and examine the military architecture from its era of operation.

Battery Gadsden was built in 1903–1904 as part of a line of batteries from Fort Moultrie to the eastern end of Sullivan's Island. It was named after Christopher Gadsden and housed four six-inch guns until decommissioned in 1917. It was listed on the National Register of Historic Places in 1974.

The battery now houses the Edgar Allan Poe Branch of the Charleston County Public Library, a branch named for the writer who was stationed at Fort Moultrie on Sullivan's Island in 1827–1828 and later set stories there. Visitors come to borrow books inside a former gun emplacement rather than to see exhibitions.

The battery now holds the Edgar Allan Poe Branch of the Charleston County Public Library, so visiting hours follow the library's opening times rather than those of a monument. The structure sits on Sullivan's Island near Battery Thomson, its neighbour at the mouth of Charleston Harbor. The ocean side stands about 7 feet high, while the battery runs some 377 feet long and 84 feet wide.

Battery Gadsden was built in 1903–1904 at the same time as Battery Jasper, and the two are often paired in accounts of the harbor defenses. Its neighbor Battery Thomson stood beside it at the mouth of Charleston Harbor. The battery was named for Christopher Gadsden, and since 1974 it has been listed on the National Register of Historic Places.