Badelundaåsen (English: Badelunda ridge) is a long and large esker in central Sweden.
It runs from the region of Nyköping in Södermanland to lake Siljan in Dalarna, and is known for many ancient monuments, especially near Badelunda outside of Västerås.
The ancient road from the Mälaren Valley to Norrland and Norway followed Badelundaåsen in long stretches.
Due to the strategic importance of the intersection, a medieval fortification Grådö skans was built, itself a precursor to Borganäs in Borlänge.
On March 29, 1520, during the Swedish war of liberation, the Danish army defeated rebelling Swedes at the battle of Badelundaåsen.