Born in Bristol, England, Veronica is the older sister of the popular child actress Angela Cartwright. In her early career, Veronica was cast in a number of popular movies such as William Wyler's The Children's Hour (1961), Spencer's Mountain (1963) and Alfred Hitchcock's The Birds (1963). As such, she was cast as "Jemima Boone" in the popular television series Daniel Boone (1964), in which she appeared during the first two seasons from 1964 to 66. Her career after "Daniel Boone" may have been influenced by Hitchcock, since she appeared in both the remake of Invasion of the Body Snatchers (1978) and the horror classic Alien (1979). On television, she appeared twice as Lumpy's younger sister, "Violet Rutherford" and once as "Peggy MacIntosh" on Leave It to Beaver (1957) and had a small role in the television movie Still the Beaver (1983).

Cartwright also appeared in Robert Kennedy and His Times (1985), Tanner '88 (1988) and had a recurring role on L.A. Law (1986). Her big screen features included The Right Stuff (1983), Flight of the Navigator (1986) and The Witches of Eastwick (1987). Veronica worked on the stage in "Electra", "Talley's Folly", "Homesteaders", "Butterflies are Free" and "The Triplet Connection". Alternating between television and big screen movies in the 90s, Cartwright has appeared in such films as Hitler's Daughter (1990) and Candyman: Farewell to the Flesh (1995).