- Category : Fencer
- Type : MGP
- Profile : 6/2 - Role Model / Hermit
- Definition : Split - Small (20)
- Incarnation Cross : LAX Uncertainty 1
Greg Massialas (born 20 May 1956 in Greece) is an American fencer. He competed in the foil events at the 1984 and 1988 Summer Olympics.
He is the founder and head coach of the Massialas Foundation (The M-Team), a fencing club in San Francisco.