Plato made her acting debut at the age of 10, making a brief appearance on the ABC television show The Six Million Dollar Man. She then starred in the 1975 made-for-television film Beyond the Bermuda Triangle. Plato made her film debut at the age of 13 in the uncredited role of Sandra Phalor in the horror film Exorcist II: The Heretic (1977). She starred as Evie Joe in the horror film Return to Boggy Creek in the same year. Both films were received negatively by critics. Better received was the family-comedy film California Suite (1978), in which Plato played Jenny Warren; the film was also a commercial success, and earned accolades at the Academy Awards and the Golden Globe Awards. thumb|The cast of Diff'rent Strokes with guest star Nancy Reagan on set in 1983|leftWhen Plato made a brief appearance on The Gong Show, she was spotted by a producer who helped cast her as Kimberly Drummond, the older sister of adopted brothers Arnold and Willis Jackson, on the NBC/ABC sitcom Diff'rent Strokes. The series debuted in 1978 and became an immediate hit. Plato appeared regularly on the show throughout its run, notably top-billed for four years. She was nominated for a Young Artist Award for her work on the program, and also was part of two TV Land Award nominations given to its cast. In 1984, following the birth of her son Tyler, Plato was dismissed from her starring role due to both her pregnancy and struggles in her personal life, which producers felt would negatively impact their "wholesome family comedy". She made a one-episode appearance on season 8 episode 12 of "The Love Boat". Thereafter, Plato appeared recurringly on Diff'rent Strokes from 1985 to 1986, the show's end; in season 8, the episode which aired on January 17, 1986, was Plato's final appearance on the show, which showed her character suffering from bulimia. CBC News described her performance in the episode as a "series highpoint".
Plato made her acting debut at the age of 10, making a brief appearance on the ABC television show The Six Million Dollar Man. She then starred in the 1975 made-for-television film Beyond the Bermuda Triangle. Plato made her film debut at the age of 13 in the uncredited role of Sandra Phalor in the horror film Exorcist II: The Heretic (1977). She starred as Evie Joe in the horror film Return to Boggy Creek in the same year. Both films were received negatively by critics. Better received was the family-comedy film California Suite (1978), in which Plato played Jenny Warren; the film was also a commercial success, and earned accolades at the Academy Awards and the Golden Globe Awards. thumb|The cast of Diff'rent Strokes with guest star Nancy Reagan on set in 1983|leftWhen Plato made a brief appearance on The Gong Show, she was spotted by a producer who helped cast her as Kimberly Drummond, the older sister of adopted brothers Arnold and Willis Jackson, on the NBC/ABC sitcom Diff'rent Strokes. The series debuted in 1978 and became an immediate hit. Plato appeared regularly on the show throughout its run, notably top-billed for four years. She was nominated for a Young Artist Award for her work on the program, and also was part of two TV Land Award nominations given to its cast. In 1984, following the birth of her son Tyler, Plato was dismissed from her starring role due to both her pregnancy and struggles in her personal life, which producers felt would negatively impact their "wholesome family comedy". She made a one-episode appearance on season 8 episode 12 of "The Love Boat". Thereafter, Plato appeared recurringly on Diff'rent Strokes from 1985 to 1986, the show's end; in season 8, the episode which aired on January 17, 1986, was Plato's final appearance on the show, which showed her character suffering from bulimia. CBC News described her performance in the episode as a "series highpoint".