G. Harry Stein was a Human Starfleet officer of the mid-24th century.
In 2364 he held the rank of captain and was the commanding officer of the USS White Sands. In that year, prior to stardate 41775, he received a mission order about the Rigel/Andor subspace relays from Commodore Peter Bryce of Starfleet Advanced Technologies Division. (TNG: "Conspiracy")
This character was never mentioned in dialog; his name from a mission order.
Stein might be named after the rocketry pioneer G. Harry Stine
; if so, the captain's name might be a misspelling.