Bacchius of Tanagra, (or Baccheius, Greek: Βακχεῖος), (3rd century BC), was one of the earliest commentators on the writings of Hippocrates and was a native of Tanagra in Boeotia. He was a follower of Herophilus, and a contemporary of Philinus. Therefore, he must have lived in the 3rd century BC. Of his writings, (which were both valuable and interesting) nothing remains but a few fragments preserved by Erotianus and Galen, by whom he is frequently mentioned.