Widdebierg ( lëtzebuergesch ) Widdenberg ( German ) is a mountain in the municipality of Betz village in eastern Luxembourg. With 386 meters, it is one of the highest elevations in the canton Grevenmacher. The mountain is located in the middle of the nature reserve Widdebierg between the towns Flaxweiler, Mensdorf and Roodt -sur- Syre.

On the Widdenberg two Celtic inscriptions were found, the name the local deities Veraudunus and Inciona.