Gillis is a masculine given name. Notable people with the name are as follows:
Gillis Ahlberg (1892–1930), Swedish rower Gillis Backereel (1572–1662), Flemish painter Gillis Berthout (1175/80–1241), Dutch nobleman Gillis Bildt (1820–1894), Swedish politician Gillis Claeissens (1526–1605), Flemish painter Gillis Coignet (c. 1542 – 1599), Flemish painter Gillis II Coignet (1586–1641), Flemish painter Gillis van Coninxloo (1544–1607), Flemish painter Gillis d'Hondecoeter ((c. 1575-1580–1638), Dutch painter Gillis Hooftman (1521–1581), Dutch merchant Gillis Grafström (1893–1938), Swedish figure skater Gillis William Long (May 4, 1923 – January 20, 1985) American Politician and Lawyer, Member of The House of Representatives for Louisiana Gillis Lundgren (1929–2016), Swedish furniture designer Gillis Mostaert (1528–1598), Flemish painter Gillis Neyts (1618 or 1623–1678), Flemish painter Gillis Schagen (1616–1668), Dutch painter Gillis van Tilborgh (c. 1625 – c. 1678), Flemish painter Gillis Valckenier (1623–1680), Dutch politician Gillis Wilson (born 1977), American football player Gillis Williams (born 1998), Autism activist, more commonly known as Gillis Willis