The 2017 1. divisjon (referred to as OBOS-ligaen for sponsorship reasons) was a Norwegian second-tier football league season.

[1] In the 2016 1. divisjon, Kristiansund and Sandefjord were promoted to the 2017 Eliteserien, while Bryne, Hødd, KFUM Oslo and Raufoss were relegated to the 2017 2. divisjon.

Bodø/Glimt and Start were relegated from the 2016 Tippeligaen, while Tromsdalen, Elverum, Florø and Arendal were promoted from the 2016 2. divisjon.

The third to sixth-placed teams took part in the promotion play-offs; these were single leg knockout matches, two semi-finals and a final.

The winners, Ranheim, advanced to play the 14th placed team in Eliteserien over two legs in the Eliteserien play-offs for a spot in the top-flight next season.