Gerhard VI "the Quarrelsome", Count of Oldenburg (German: Gerhard (Gerd) der Mutige von Oldenburg; 1430 – 22 February 1500) was a Count of Oldenburg and regent of Bad Zwischenahn in 1440–1482.
Gerhard was the third son of Dietrich of Oldenburg and his wife, Helvig of Schauenburg. His eldest brother succeeded their father as Christian VII but was elected King Christian I of Denmark in 1448, therefore passing on the county to his brothers in 1450. In 1440–1463 Gerhard VI ruled in Delmenhorst as regent and in 1464–1482 (after the death of his brother Maurice) as the guardian of his nephew Jakob. He was constantly at war with Gerhard III, Prince-Archbishop of Bremen, and Frisians. In 1483 Gerhard was compelled to abdicate in favor of his sons, and he died whilst on a pilgrimage in the Rhône valley.