Claude was born in 1604 or 1605 into poverty in the town of Chamagne, Vosges in Lorraine – then the Duchy of Lorraine, an independent state until 1766 and now in northeast France. He was one of five children. His actual name was Claude Gellée, but he is better known by the province in which he was born. Orphaned by age of twelve, he went to live at Freiburg with an elder brother, Jean Gellée, a woodcarver. He afterwards went to Rome to seek a livelihood and then to Naples, where he apprenticed for two years, from 1619 to 1621, under Goffredo (Gottfried) Wals. He returned to Rome in April 1625 and was apprenticed to Agostino Tassi. He got into a fight with Leonaert Bramer.
He apparently was able to tour in Italy, France and Germany, including his native Lorraine, suffering numerous misadventures. Claude Deruet, painter to the duke of Lorraine, kept him as assistant for a year; and at Nancy he painted architectural subjects on the ceiling of the Carmelite church.