A metastable transformative Fe39Mn20Co20Cr15Si5Al1 high entropy alloy (Al-HEA) was friction stir butt welded with Al-7050 alloy. Extensive mechanical mixing was evident in the weld nugget wherein sheared HEA particles were dispersed in Al-alloy matrix. Detail investigation of the weld interface showed suppression of intermetallic formation thereby approaching a clean interface. Tensile testing of the weld nugget showed a strength of 400 MPa with ~ 10% ductility whereas corrosion testing showed no sign of extensive pitting at the Al-HEA/Al-7050 weld interface. Therefore, use of high entropy alloy is an effective pathway for obtaining strong dissimilar joints with high strength Al alloys for lightweight applications. © 2020