For the similarly-named male ensign, please see Masaro.
Ensign Massaro was a female member of Commander Charles Tucker's engineering team on board Enterprise NX-01.
In 2153, T'Pol ordered Sim, a clone of Tucker, to assist Massaro in running a diagnostic on the plasma assembly, as part of the crew's efforts to escape from a polaric field in which Enterprise had become trapped. (ENT: "Similitude")
This character was only mentioned in dialogue.