"Onesimos" means "profitable" in Greek and may have been a nickname. Onesimos worked in Athens in the early 400s B.C. decorating vases. He painted vases primarily in the red-figure technique, but he also decorated some white-ground vases. Although many vase-painters tended to specialize in certain types of vases, Onesimos was unusual in the degree to which he decorated cups almost exclusively. He frequently decorated vases potted by Euphronios and seems to have learned many elements of his painting style from this artist.
Continuing the work of his master and the other Pioneers, Onesimos favored active poses and realistic renderings of the human body, including elements such as body hair and receding hairlines. His mythological depictions were innovative: many myths appear for the first time in his work. In his later work Onesimos emphasized scenes of everyday life, especially symposia and athletes.