- See Kirk for other articles with titles that contain, either by relationship or by coincidence, this character's surname.
Tiberius Samuel Kirk, known to his grandson as Samuel, was the father of James Kirk and George Samuel Kirk, Sr.. Perhaps due to his first name, he had a fascination with the Roman emperor Tiberius. Tiberius' name was also given to his grandson, James Tiberius Kirk. (TOS novelizations: Star Trek: The Motion Picture, Star Trek)
His father was Samuel Abraham Kirk, who served as the ship's historian aboard the USS Pioneer, one of the first Federation Starfleet vessels, in the 2160s. (ENT - Rise of the Federation novel: A Choice of Futures)
In the Kelvin timeline, Tiberius' daughter-in-law Winona Kirk suggested Tiberius' name when she and George were naming their newborn son. George rejected that name, instead suggesting Winona's father's name, Jim, though Tiberius was still used as Jim Kirk's middle name in this reality as well. (TOS movie: Star Trek)
- His first name, Tiberius, was given in the film Star Trek. Prior to that, he was only referred to as "grandfather Samuel", in the novelization of Star Trek: The Motion Picture.
- According to The Autobiography of James T. Kirk, Tiberius Kirk passed away in 2232 when his son George Kirk, Sr. learned that George's wife, Winona was pregnant with their second son, James T. Kirk.