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)
Nearly one month after the V'Ger Incident, she spoke in favor of Kirk's administrative and command decisions. During and after the crisis, she hid a secret crush for the newly-demoted Admiral. (TOS novel: Ex Machina)
- Though she was not a true member of "Kirk's women", author Christopher Bennett decided to write this gag referring to William Shatner's real-life marriage to the actress who played DiFalco, Marcy Lafferty.
DiFalco, Hikaru Sulu and Pavel Chekov became involved in a barroom brawl on Yannid VI between supporters of the Federation and rebel sympathizers who wanted the planet to join the Klingon Empire. (TOS comic: "The Enterprise Murder Case!") On a landing party searching for Commander Spock on Agena IV, DiFalco had her phaser shot out of her hand by an Org projectile weapon. Later, she tried to stun one of the native creatures called Kamahr for use as a lab specimen, leading Kirk to chastise her for potentially violating the Prime Directive. (TOS comic: "The Expansionist Syndrome") DiFalco was one of only nine Enterprise crewmembers left unaffected when Dr. Carl Wentworth attempted to take over the ship by using mind control on the crew. (TOS comic: "... Like a Woman Scorned!") On a mission to Zeta Reticuli II, DiFalco helped Chekov and Uhura save the life of Dr. Leonard McCoy by firing their phasers at the neck-joint of a robot sphinx, decapitating it before it could kill him. (TOS comic: "We Are Dying, Egypt, Dying!")
- TOS novel: A Flag Full of Stars
- TOS movie, novelization & comic adaptation: Star Trek: The Motion Picture
- TOS - Untold Voyages comic: "Renewal" (no dialogue)
- TOS novel: Ex Machina
- TOS novel: Provenance of Shadows
- TOS comic: "The Enterprise Murder Case!"
- TOS comic: "Aberration on Abaris"
- TOS comic: "The Expansionist Syndrome"
- TOS comic: "... Like a Woman Scorned!"
- TOS - Mere Anarchy eBook: The Darkness Drops Again
- TOS comic: "There's No Space Like Gnomes'!" (no dialogue)
- TOS comic: "Husian Gambit" (no dialogue)
- TOS comic: "It's a Living" (no dialogue)
- TOS comic: "Quarantine (comic strip)" (no dialogue)
- TOS comic: "The Nogura Regatta"
- TOS comic: "We Are Dying, Egypt, Dying!"
- TOS - Untold Voyages comic: "Silent Cries" (no dialogue)