Patricia F. O'Malley was a Starfleet ensign who served aboard the Enterprise NX-01 during its mission in the Delphic Expanse in 2154.
In that year, O'Malley was one of a number of Enterprise crewmembers killed in battle with the Xindi. Later that year, after Enterprise ahd traveled back in time to the year 1944 of an alternate timeline, Captain Archer allowed Alicia Travers, a native of the time period, to stay in O'Malley's quarters during her brief stay aboard they ship. (ENT: "Storm Front, Part II")