Folcwine was the fourteenth King of Rohan and the fifth king of the second line. He was the son of Folca.

During his reign the Rohirrim finally recovered their full strength after the desolation of the Long Winter. They reconquered the lands of the West-march, between the Rivers Adorn and Isen, from the Dunlendings.

King Folcwine heard news that the Haradrim were assailing the lands of Gondor so he sent many Rohirrim to their aid. He had wished to go and lead his men himself but instead sent his twin sons Folcred and Fastred.

When the twins were slain in Ithilien, Túrin of Gondor sent to Folcwine a great weregild of gold.

Folcwine was then succeeded by his son Fengel.