J. Thomas was a Human Starfleet officer in the 22nd century.
In 2154, he was listed as an Environmental Systems officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque)
In January 2155, he was listed as a CAPCOM officer on directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #3543. (ENT: "Demons", directories)
This character was only mentioned in writing.
He was named after Enterprise costumer Jamie Thomas.