Fabian Gottlieb von Bellingshausen (Беллинсгаузен, Фаддей Фаддеевич, Faddey Faddeyevich Bellinsgauzen in Russian) (September 20, 1778 - January 13, 1852) was a naval officer of the Russian Empire and leader of the second expedition to circumnavigate Antarctica.

Born in Ösel, Estonia in the Russian Empire, Bellingshausen was enlisted as a cadet in the Russian Imperial Navy at the age of 10. After graduating from the naval academy at Kronstadt at age 18, he rapidly rose to the rank of captain. As a great admirer of Cook's voyages, he was chosen to lead the first Russian circumnavigation of the earth in 1803, completing the mission in 1806.

When Czar Alexander I authorised an expedition to the south polar region in 1819, Bellingshausen was again chosen to lead. Leaving Portsmouth on September 5, 1819 with two ships, the 600-ton corvette Vostok and the 530-ton support vessel Mirnyi (captain - Mikhail Petrovich Lazarev), the expedition was only the second ever to cross the Antarctic Circle on January 26, 1820.

Bellingshausen's log shows that he made it to within 20 miles of the Antarctic mainland, but failed to recognise it as such at the time. Despite this, he is claimed by some to be the discoverer of the sought-after Terra Australis rather than the English Edward Bransfield or American Nathaniel Palmer. During the voyage he discovered and named the South Shetland Islands, Peter I Island and a peninsula of the Antarctic mainland which he named Alexander Coast but which has more recently been redesignated Alexander Island.

Returning on 4 August 1821 to no great acclaim, Bellingshausen continued to serve his country as an Admiral and Governor of Kronstadt until his death in 1852.