The 2003 Toppserien was the 17th season of the Toppserien, the highest level of women's football (soccer) in Norway. The league commenced on April 26, 2003, and concluded on October 11, 2003. Ten teams competed in the season, playing a double round-robin format, meaning each team played 18 matches.
Kolbotn IL secured their first-ever Toppserien championship title, finishing the season with 43 points. They narrowly edged out Trondheims-Ørn SK, who finished in second place with 42 points. The top goal scorer for the 2003 season was Ragnhild Gulbrandsen of Trondheims-Ørn, who scored 18 goals.
At the conclusion of the season, Larvik FK finished last in the league table and was consequently relegated to the First Division (1. divisjon). They were replaced by the promoted teams from the First Division, Fløya and Liungen, for the subsequent 2004 Toppserien season.