Films:
* The Running Man (1987) - As Amber Mendez, a competitor on the deadly game show.
* The Sure Thing (1985) - As the alluring and intelligent "Rhonda."
* Killjoy (1989) - As the fierce demon hunter, "Linda."
* Mannequin (1987) - As "Brenda," a beautiful and passionate mannequin who comes to life.
* Predator 2 (1990) - As "Danny's Wife," a minor but memorable role.
* A Dangerous Woman (1993) - As the titular character, a dangerous and alluring woman.
* The Adventures of Elmo in Grouchland (1999) - As the voice of "Rosita."
* The Woman in Red (1984) - As "Carla."
Television:
* "The Nanny" (1995-1999) - As "Mamou" (Recurring role)
* "Hotel" (1983-1988) - As "Carmen Sandiego" (Recurring role)
* "Fantasy Island" (1978-1984) - As "Maria" (One episode)
* "The Love Boat" (1977-1986) - As "Alicia" (One episode)
* "The Bold and the Beautiful" (1987-present) - As "Dona Dominguez" (Recurring role)
* "General Hospital" (1963-present) - As "Marcela" (Recurring role)
* "Touched by an Angel" (1994-2003) - As "Carmen" (One episode)
* "The New Adventures of Old Christine" (2006-2010) - As "Brenda" (One episode)
* "The Mysteries of Laura" (2014-2016) - As "Gloria" (One episode)
* "Supergirl" (2015-present) - As "Mama Maggie" (Recurring role)
* "Desperate Housewives" (2004-2012) - As "Adriana" (One episode)
This is not an exhaustive list, as Maria Conchita Alonso has appeared in a variety of other films and television shows throughout her career.
It is important to note that this list reflects her more notable roles, and does not include every single project she has participated in.