This page details George Samuel Kirk, Jr. in the alternate reality created by Nero's temporal incursion; for the George Samuel Kirk, Jr. in the primary universe see George Samuel Kirk, Jr.; for the George Samuel Kirk, Jr. in the mirror universe see George Samuel Kirk, Jr. (mirror); for the George Samuel Kirk, Jr. in all other alternate universes see George Samuel Kirk, Jr. (alternates).

George Samuel Kirk, Jr. was the eldest son of Winona and George Samuel Kirk, Sr., and brother of James T. Kirk. He was born on 12 August 2230. (TOS novel: The Last Roundup)

Kirk's father died in 2233 at the hands of the Romulan miner Nero, on the same day that his brother James was born. Eventually Winona remarried to a man named Frank. Both George and his younger brother found living with Frank to be intolerable, and George eventually ran away from home - with his younger brother Jim following him in their father's antique Corvette that Frank was going to sell while Winona was off world. (TOS novel: Star Trek)