The 1998 1. divisjon, Norway's second-tier football league, began play on 19 April 1998 and ended on 18 October 1998. The league was contested by 14 teams, and the top two teams won promotion to Tippeligaen, while the third placed played a promotion-playoff against the 12th-placed team in Tippeligaen to win promotion. The bottom four teams were relegated to the 2. divisjon.