Solid is the fifth studio album by German heavy metal band U.D.O. It is the first in six years, when frontman Udo Dirkschneider put the band on hiatus and reunited with Accept. Accept's drummer Stefan Kaufmann joined U.D.O. as a guitar player on this album. Guitarists Fitty Weinhold and Jürgen Graf from Bullet were hired as new members.
The album was recorded and mixed at Roxx Studios in Pulheim.[3]