Baldwin VI of Flanders (died July 17, 1070) was briefly Count of Flanders, from 1067 to 1070. He was also (as Baldwin I) count of Hainaut from 1051 to 1070.

He was the eldest son of Baldwin V of Flanders and Adela Capet, a daughter of king Robert I of France.

In 1051 he married Richilda, widow of count Hermann I of Hainaut. Flanders had taken control of Hainaut, but it was only by this marriage that possession was really secured.

Baldwin's early death left Flanders and Hainaut in the hands of his young son Arnulf III, with Richilda as regent. The countship was soon usurped by Baldwin's brother Robert the Frisian, who became count Robert I of Flanders. The young Arnulf III was killed the next year at the Battle of Cassel, and Baldwin's younger son eventually became Baldwin II of Hainaut.

See also: Counts of Flanders family tree - Counts of Hainaut family tree