Simen Agdestein (born 15 May 1967) is a Norwegian who has excelled in chess, chess coaching and football. He is also an author of several books.Agdestein is a chess grandmaster. He has won seven Norwegian chess championships, including the 2005 title. He is also the former coach of Magnus Carlsen, and is the brother of Carlsen's present manager, Espen Agdestein.