J. Billingsley was a Human Starfleet officer in the 22nd century.

In January of 2155, he was listed as a Surgeon on one of the directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #5550. (ENT: "Demons", United Earth directory)

This character was only mentioned in writing.
He was named after Star Trek: Enterprise actor John Billingsley, who played Phlox, the chief medical officer aboard Enterprise NX-01.