Rey Alfonzo was a Federation Starfleet officer assigned to Deep Space 9 in the late 2370s. In June 2376, Lieutenant Alfonzo collected sensor signatures of Ambassador Seljin Gandres and Hiziki Gard when they were welcomed to Deep Space 9 by Colonel Kira Nerys. He then escorted Gard to the Trill delegation's quarters. (DS9 - Mission Gamma novel: Twilight) In December, 2377, following the destruction of the Ascendant invasion fleet over Bajor, Alfonzo crewed the USS Volga along with Ensign José Chavez to intercept the lone surviving Ascendant Raiq. (DS9 novel: Ascendance)