Claes Reimerthi is a literary, comic writer and comic historian.

He has written for most of the major Swedish-produced series, including Phantom (Fantomen), 91:an and Little Fridolf. He is currently magazine Phantom's lead author and responsible for the creative development of that series of comic books.

During 2000-2003, he wrote a number of episodes of the American version of The Phantom newspaper. Claes Reimerthi has teamed up with notable artists like Dick Giordano, Hans Lindahl, Joan Boix and Paul Ryan, among others, to create excellent Fantomen stories in the last two decades.

He is an honorary member of The Scandinavian Chapter of the Lee Falk Memorial Bengali Explorers Club.