Mjøndalen had a successful 2008 in 2. divisjon, and returned to 1. divisjon for the 2009 season. The club qualified to compete in the promotion knock out stage of 1. divisjon in both 2012 and 2013, and finally earned promotion to the Tippeligaen with a successful 2014 play-off result against Brann. Mjøndalen's return to Tippeligaen for 2015 marked their first appearance in the top tier in 22 years. The team finished in 15th place — second from bottom — and was relegated to the 2016 1. divisjon. In 2018, Mjøndalen finished in second place in the 2018 1. divisjon and was promoted to Eliteserien. In the following season, Mjøndalen succeeded in retaining their spot in the top flight through winning on the last day of the season.