L. Castro was a Human Starfleet officer in the 22nd century.

In 2151, she was listed as a Propulsion Systems officer on the dedication plaque of Enterprise NX-01. (ENT: "Broken Bow", dedication plaque).

In January of 2155, she was listed as a Payloads officer on directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #4244. (ENT: "Demons", directories)

This character was only mentioned in writing.
She was named after VOY and ENT visual effects coordinator Elizabeth "Liz" Castro.