Ernest I, Duke of Brunswick-Göttingen

Ernest I (c. 1305–24 April 1367) was a son of Albert II the Fat of Brunswick-Wolfenbüttel and Rixa of Werle. When his childless brother Otto the Mild died in 1344, he and Magnus I divided the Welf lands, and Ernest took the Principality of Göttingen, the poorest of the Welf domains, formed from the old Northeim holdings. The split parted Göttingen from Brunswick for a long time, though the city of Brunswick itself stayed with the whole house.

Ernest ruled Göttingen until his death. In 1339 he married Elizabeth, daughter of Landgrave Henry II the Iron of Hesse; she bore him six children, including his successor Otto I.

He is believed to have fought alongside local cities against the robber barons around Göttingen, and in 1364 he joined a regional coalition in a war on the Bishopric of Hildesheim.