Claes Nyberg (born 3 March 1971) is a Swedish former long-distance runner who competes mostly in cross country running.

His highest international achievement was a silver medal at the 1997 European Cross Country Championships.

He made seven appearances at the IAAF World Cross Country Championships between 1989 and 2002, with his best placing of 33rd coming both 2000 and 2001.

Nyberg won fourteen individual national titles during his career.

[1] He was a perennial runner-up at the Nordic Cross Country Championships, taking the second spot on five occasions between 1997 and 2002.