Gregory Jein (also known as Greg Jein) was a Starfleet officer in the 24th century. He was a captain in 2363. In 2368, he was listed as a Yard Engineer on the second version of the dedication plaque of the USS Enterprise-D. (TNG: "Silicon Avatar" , dedication plaque) In the 2370s, he was listed as a Tactical Operations officer on the dedication plaque of several Federation starships. (DS9: "The Search, Part I", dedication plaque; VOY: "Caretaker", dedicaton plaque; DS9: "The Dogs of War", dedication plaque)