The old Division 1 replaced Division 2 as the second highest level in 1987 and consisted of two separate leagues with 14 teams each, Norra (Northern) and Södra (Southern), except for the 1991 and 1992 seasons which comprised 32 teams in four leagues, adding Östra (Eastern) and Västra (Western).

As of the 2018 season, both Norra and Södra leagues of Ettan are composed of 16 clubs, similar to Allsvenskan and Superettan.

There are 32 clubs in Ettan, divided in two groups of 16 teams each representing Northern and Southern Sweden.

During the course of a season (starting in April and ending in November) each club plays the others twice, once at their home stadium and once at that of their opponents, for a total of 30 games.

[2] Note: In 2007 the runners up were promoted automatically without playoffs because of Allsvenskan expanding to 16 teams.