Harris was born in San Fernando, California and placed in a Los Angeles orphanage shortly after her birth. She was adopted by an area couple when she was a month old. Shortly after her adoption, she appeared in a Rin Tin Tin film. In her later years, Harris revealed that her adoptive mother forced her to pursue a screen career because of her own failed attempts to become an actress.^[1] Harris also claimed that her mother was physically and emotionally abusive.^[2]

In 1931, Harris won the role of "Little Maria" in the horror film Frankenstein. In arguably the film's most memorable scene, Maria meets the fugitive monster (played by Boris Karloff) beside a lake and charms the monster with her innocence, humanity and friendship. These were qualities that he had not experienced with hostile, untrusting adults. A children's game is tragically misinterpreted by the monster, and he throws Little Maria into the lake,^[3] unintentionally drowning her and turning the surrounding village's population into a lynch mob, seeking revenge after the child's body is found. The shot of Maria being thrown into the water was cut from original prints, and was restored in the 1980s.

After appearing in Frankenstein, Harris continued her career in small film roles. She left acting at the age of 19 shortly after marrying Wally Watkins, a bouncer she met while working as a cashier at the Hollywood Palladium. The couple had a son the following year. After Harris' husband died in 1981, she remarried. Harris' second husband, Carl, died in 1988.^[4]

• Marilyn Harris at IMDb