Giannis \gi(an)-nis\ as a boy's name is a variant of John (Hebrew), and the meaning of Giannis is "God is gracious".

The baby name Giannis sounds like Giannos and Giannes. Other similar baby names are Gianni, Gianny, Gianney, Giannino, Jianni, Ioannis, Tannis and Yannis.