Marktheidenfeld is a town in the Main-Spessart district in the Regierungsbezirk of Lower Franconia (Unterfranken) in Bavaria, Germany, and the seat of the Verwaltungsgemeinschaft of Marktheidenfeld. The town has around 11,000 inhabitants.

Lower Franconia is one of seven districts of Bavaria, Germany. The districts of Lower, Middle and Upper Franconia make up the region of Franconia. It consists of nine districts and 308 municipalities.