Dag Fornæss (born 30 June 1948) is a former speed skater from Norway who won the Norwegian, European, and World Allround Championships in 1969.

Representing Hamar Idrettslag (Hamar Sports Club), Fornæss had his international breakthrough in 1969, when he won the Norwegian Allround Championships, the European Allround Championships, and the World Allround Championships.

Fornæss participated in his last international event at the 1972 Winter Olympic Games, after which he ended his skating career.

Fornæss also was a successful association football player, playing in the Norwegian Premier League for the club Skeid Fotball in 1972.

[1] An overview of medals won by Fornæss at important championships he participated in, listing the years in which he won each: Fornæss successively broke the 3,000 m record twice.