Tom is the first-born son of Amy Jennings, making him the great-grandson of Lenore Filmore and the great-great grandson of Quentin Collins and Jenny Collins. He was named in honor of his maternal uncle, Tom Jennings who died before he was born. His other uncle, Chris Jennings, also died prior to his birth. Like Chris, Tom inherited the curse of the werewolf.
Tom has a close relationship with his mother, and supports her planned marriage to David Collins.
Born half-English and half-American, he was taken by his parents to Collinsport while he was still a baby. Due to his father's carelessness, Tom instantly aged into a teenager before his mother's eyes. Consequently, he has the appearance of a teenager but still makes childish mistakes (Bloodlust). His father was killed, and his mother eventually began a romantic relationship with David Collins.