Gillis \gi(l)-lis\ as a boy's name is a variant of Giles (Greek), Gillespie (Irish, Gaelic) and Gillies (Scottish, Gaelic), and the meaning of Gillis is "small goat; son of the bishop's servant; servant of Jesus".

The baby name Gillis sounds like Gilliss and Gilles. Other similar baby names are Willis, Callis, Collis, Dallis, Ellis, Gill, Gillby, Gillbie, Gilley, Gillon, Gillion, Gillian, Gillen, Gillan, Ghillies, Ghilles, Gili, Giulio, Hollis, Mills, Sills, Tallis, Tullis, Wallis, Wills, Williss and Willes.