St. Onesimus, was a 4th-century bishop and pre-congregational saint of France. He was the fifth bishop of Soissons,Saint Onesimus of Soissons at Saints.SQPN.com. being appointed about 350 AD and holding office till 361 AD.
He died in 361 AD and his feast day is May 13.St. Onesimus at Catholic Online.
References