Adam Duce (born April 14, 1972) is an American musician, best known as a founding member and former bassist of the heavy metal band Machine Head.

After getting out of the reform school, Mader introduced him to metal music with bands such as Slayer, Metallica, Exodus, King Diamond, Celtic Frost and Sacrilege B.C.

Retaining a desire to write music, Flynn recruited Duce, guitarist Logan Mader and drummer Tony Costanza to form Machine Head.

In an interview, he admitted that he wrote several riffs and lyrics that got rejected by Robb Flynn, which led to further disagreements between him and the band.

[7] On January 21, 2014, Duce filed a lawsuit against Machine Head's then-remaining members (Flynn, Phil Demmel and Dave McClain) and manager in Federal Court, alleging trademark infringement, breach of partnership agreement and defamation, among other things.