Her credits include: Buck Rogers in the 25th Century, Flamingo Road (as Alicia Sanchez), Remington Steele, Airwolf, Rituals (as Diandra Santiago Gallagher), Knight Rider, Lust in the Dust, Santa Barbara (as Santana Andrade), Seinfeld, Beverly Hills, 90210, ER, NYPD Blue, JAG and The O.C.
[citation needed] Gallego was discovered in Hollywood by the Alvarado Talent Agency, and within weeks was cast opposite of Jon Voight in director Franco Zeffirelli's’s The Champ.
She was featured on Santa Barbara (1984), where she played Santana Andrade, a Mexican maid who had a baby boy out of wedlock with wealthy playboy Channing Capwell Jr, and was forced into giving him up for adoption.
Santana's storylines were dominated by her attempts to reclaim her child, and her long-running feud with her son's villainous adoptive mother Gina Capwell (Robin Mattson).
[citation needed] In Erin Brockovich (2000), Gallego was cast as a Pacific Gas & Electric attorney who defends the utility company against allegations they caused carcinogens to poison drinking water in Hinkley, CA.