William Speirs Bruce (August 1, 1867–October 28, 1921) was a London-born Scottish naturalist, polar scientist and oceanographer who organized and led the Scottish National Antarctic Expedition (1902–04). He also made many journeys to the Arctic regions, both for scientific and for commercial purposes.
Bruce had initially intended to study medicine, but his outlook changed after he attended extra-curricular courses in the natural sciences during the summer of 1887. After these courses he began to develop a wider range of scientific interests, and in 1892 he abandoned his medical studies at the University of Edinburgh, to join the Dundee Whaling Expedition to Antarctica as a scientific assistant. This was followed by Arctic voyages to Novaya Zemlya, Spitsbergen and Franz Josef Land (where he met Fridtjof Nansen).
In 1899 Bruce applied for a scientific post on the British National Antarctic Expedition (later known as the Discovery Expedition). Delays in confirming this appointment, and differences with Royal Geographical Society (RGS) president Sir Clements Markham, led him instead to organize his own expedition to the South Orkney Islands and the Weddell Sea—the Scottish National Antarctic Expedition (SNAE). Bruce later founded the Scottish Oceanographical Laboratory in 1906, but his subsequent Antarctic plans—a proposed transcontinental march via the South Pole—were thwarted through lack of public and financial support. These plans were adopted by Sir Ernest Shackleton as the basis for his Imperial Trans-Antarctic Expedition, 1914–17.