NorthSide Festival, or simply NorthSide, is a three-day music festival held every year in June in Aarhus, Denmark. It has three stages with rotating artists and several sideshow events and happenings. The first festival commenced in 2010 and since 2011, the festival has been held at Ådalen in Åbyhøj. The 2017 festival was attended by 40,000 people each day.
The festival now goes by the name NorthSide to avoid confusion with the Northside Festival in Brooklyn. It is a privately owned festival, owned by Down The Drain Holding, who also owns the Tinderbox music festival in Odense and is shareholder in other music business activities in Denmark.