English naval officer believed to have been the first to sight the Antarctic mainland and to chart a portion of it.

Master aboard HMS Andromache at Valparaiso, Chile, he was appointed to sail the Williams in order to chart the recently sighted South Shetland Islands, which lie near the Antarctic Peninsula. With William Smith, Bransfield arrived at the South Shetlands in January 1820, landed on King George Island to take formal possession, and coasted to Deception Island. Turning southward, he sighted and charted “high mountains, covered with snow,” possibly Mounts Bransfield and Jacquinot on the Antarctic mainland (Jan. 30, 1820). The charts survive in the hydrographic department of the British Admiralty.