Gelli may refer to:
- Giambattista Gelli, Italian humanist
- Licio Gelli, Italian fascist Freemason associated with the rogue Masonic lodge Propaganda Due or P2, accused of attempting to covertly overthrow Italy's government to establish a new Italian fascism in the late 1970s
- Ramesh Gelli, Indian bank executive
- Mynydd y Gelli, Welsh mountain
- Gelli, Pembrokeshire, hamlet in Pembrokeshire, Wales
- Gelli, Rhondda, in Rhondda Valley - a district of Ystrad
- Ardenis, Armenia, formerly Gelli