Gaius Amafinius (or Amafanius) was one of the earliest Roman writers in favour of the Epicurean philosophy. He probably lived in the late 2nd and early 1st century BC. He wrote several works, which are censured by Cicero as deficient in arrangement and style. He is mentioned by no other ancient writer but Cicero. In the Academica, Cicero reveals that Amafanius translated the Greek concept of atoms as "corpuscles" (corpusculi) in Latin.