Rohan is a realm in J. R. R. Tolkien's fantasy era of Middle-earth. It is a grassland which lies north of its ally Gondor and north-west of Mordor, the realm of Sauron, their enemy (see maps of Middle-earth). It is inhabited by the Rohirrim, a people of herdsmen and farmers who are well-known for their horses and cavalry.
Rohan is also referred to as Riddermark or the Mark. The realm is of significant importance in the author's most famous book, The Lord of the Rings.