J. Thomas was a Human Starfleet officer in the 22nd century.
In 2154, he was named as an Environmental Systems officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque).
In January of 2155, he was named as a CAPCOM officer on directory placards at the Fleet Operations Center, Sol Sector. His office was in room #3543. (ENT: "Demons", directories)