Marcella DiFalco (also known as Suzanne DiFalco) was a female human in Starfleet in the 23rd century. She served as a non-commissioned officer aboard the USS Enterprise under Captain Willard Decker, and then later under Admiral James T. Kirk, holding the rank of Chief. DiFalco replaced Lt. Ilia as navigator following her elimination by the V'Ger probe. (TOS movie, novelization & comic adaptation: Star Trek: The Motion Picture)