Simen Agdestein (1967 - ) is a Norwegian chess grandmaster and ex-football (soccer) star.

Born 15th May 1967, the young Agdestein developed a prodigious chess talent, culminating in his becoming Norway's national champion at the age of 15, an International Master at 16 and a Grandmaster at a mere 18 years of age.

On a local level, his regular dominance of the Nordic and Norwegian Championships during the 1980s amply demonstrated that there were few players who could resist his enterprising and inventive style. In international competition, his early achievements were noteworthy; he finished second at the 1986 World Junior Championship behind Walter Arencibia but ahead of Evgeny Bareev , Viswanathan Anand and Jeroen Piket . A little later, his ELO rating rose to what is commonly regarded as 'Supergrandmaster' level (in excess of 2600), although he never quite managed to break into the world elite circuit.

During 1988 and 1989, Agdestein became the envy of young men the world over, when he managed to juggle top-flight chess with a full time football career, representing his country at both.

Alas, in the early 1990s, a knee injury cut short his international football and the difficult times that followed also reflected in his chess, with his rating going into steady decline. In 1999 however, Agdestein resurrected his chess and returned to winning ways, topping the popular Cappelle la Grande tournament that year and a very strong Isle of Man tournament in 2003.

As a player of the white pieces, he shows a preference for the queen pawn openings, while with black, favours the Ruy Lopez, Dutch Defence and other semi-open games. On the April 2005 FIDE list, he had an Elo rating of 2573.

Simen Agdestein works at a sports academy, where he teaches chess and football. He is also trainer to up and coming child chess prodigy Magnus Carlsen.