Nelis is a Dutch masculine given name, a short form of the given name Cornelis, and a patronymic surname derived from it. Notable people with this name include:
- Given name
- Nelis van Dijk (1904–1969), Dutch boxer
- Surname
- Manke Nelis (1919–1993), stage name of one-legged Dutch singer Cornelis Pieters
- André Nelis (1935–2012), Belgian sailor and Olympian
- Cornelius Franciscus de Nelis (1736–1798), Flemish statesman; Bishop of Antwerp 1785–98, brother of Jan Karel
- Endel Nelis (1925–1993), Estonian fencer
- Georges Nélis (1886–1929), Belgian aviation pioneer
- Jan-Karel de Nelis (1748–1834), Flemish noble, lawyer, and pomologist, brother of Cornelius
- Named for him: Winter Nelis pear, a pear he cultivated
- Joseph Nelis (1917–1994), Belgian football striker
- Mary Nelis (1998–2004), Member of the Northern Ireland Assembly
