Quinto took birth in Pittsburgh and brought up in Green Tree which is situated in Pennsylvania. Margaret J Margo, his mother worked in investment farm and after sometime she worked in the magistrate’s office. Joseph, his father who was a barber died of cancer when he was only seven years old. Along with the brother Joe, he was grown up by their mother. His mother was of Irish, his father was of Italian and he chose to be Catholic. Quinto’s primary appearance was on the television in the short length TV series The Others. He was appeared as a guest in the shows such as Lizzie McGuire, Six Feet Under, CSI, Touched by an Angel etc. In the year 2003, at the time of the theatrical run of Endgame which was written by Samuel Beckett and directed by Kristina Lloyd he played the role of the Cloy.

He has a celtik triskelion tattoo on his left shoulder. This arm tattoo is considered as the tiny tattoo also.