In demonology Bathin is a Duke (Great Duke according to Pseudomonarchia Daemonum) of Hell, who has under his command thirty legions of demons. He knows the virtues of precious stones and herbs, and can bring men suddenly from one country to another.

He is depicted as a strong man with the tail of a serpent, riding a pale horse.

His name could derive from Latin 'batha', Ethiopian (it was believed that demons could appear in the form of a black man) or from Latin 'mathios', an undetermined herb that was believed could keep serpents young.

Other spellings: Bathym, Mathim, Marthim.