USS Harnett County (LST-821) was an LST-542-class tank landing ship built for the United States Navy during World War II. Named after Harnett County, North Carolina, she was the only U.S. Naval vessel to bear the name.
USS LST-821 was laid down on 19 September 1944 at Evansville, Indiana by the Missouri Valley Bridge & Iron Company; launched on 27 October 1944; sponsored by Mrs. Hugh Robertson, Sr.; and commissioned on 14 November 1944 with Lieutenant C. J. Rudine, USNR, in command.
During World War II, LST-821 was assigned to the Asiatic-Pacific theater and participated in the assault and occupation of Okinawa Gunto from April through June, 1945. Following the War, she performed occupation duty in the Far East until early December, 1945. LST-821 returned to the United States and was decommissioned in March, 1946 and assigned to the Pacific Reserve Fleet. On 1 July 1955 all remaining LSTs were given names of U.S. counties; LST-821 was named USS Harnett County (LST-821).