Operation: Gray Ghost (also known as Project: Grey Ghost) was the codename of a Starfleet Intelligence deep-space survey mission into Romulan space.

After learning of the Klingon Sector Group of Starfleet Intelligence making preparations for their Operation: Dixie mission in 2274, the rival Romulan Sector Group began planning a similar mission, Operation: Gray Ghost, which launched ahead of schedule in 2276. (FASA RPG module: Star Trek IV Sourcebook Update)