(23 May 1838 - 10 December 1932) was a Norwegian painter.
He was born in Halse as a son of shipmaster and merchant Niels Clemetsen Nielsen (1795 - 1845) and his wife Andrea Marie Møller (1802 - 1866). He grew up in Mandal in Vest-Agder county, Norway. He lived most of his childhood and adolescence without a father. He received some tuition from a traveling drawing teacher and traveled to Copenhagen to study in 1854