Amy O'Neill is an American actress and producer. After appearing in several sitcoms and starring as Molly Stark on The Young and the Restless in 1986, she was cast in her notable role as Amy Szalinski in the 1989 Disney film, Honey, I Shrunk the Kids, for which she was nominated for a Young Artist Award. She reprised her role as Amy Szalinski in the 1992 sequel, Honey, I Blew Up the Kid, and appeared as Lisa Barnes in Where's Rodney?

O'Neill made her first appearance on television at age 13 in an episode of Mama's Family as a younger version of Betty White's character, Ellen Harper. She continued working on television shows such as Matt Houston, Night Court, Highway to Heaven and The Twilight Zone. She also appeared on the American game show, Body Language in the summer of 1985. After an appearance on Family Ties, O'Neill won the role of the pregnant teenager Molly Stark on the daytime soap, The Young and the Restless for thirty episodes in 1986. She appeared in the 1989 television films, Desperate for Love as Tammy Lauren's best friend, with Christian Slater and as Jodie in I Know My First Name is Steven, before appearing in her most recognized role as Amy Szalinski in Honey, I Shrunk the Kids.

She acted as Lisa Barnes in the pilot episode of Where's Rodney? with Rodney Dangerfield. She continued working in television series such as Room for Romance, The Young Riders, and Gabriel's Fire, and starred as Susan Hartley in an episode of Murder, She Wrote.

She reprised the role of Amy Szalinski in the 1992 film Honey, I Blew Up the Kid, albeit only in the opening scene where she leaves for college.

O'Neill later appeared in the television film, White Wolves: A Cry in the Wild II as Pandra, one of the young adults stuck in the Cascade Mountains, having to fend for themselves. In 1994, she appeared in the National Lampoon film, Attack of the 5 Ft. 2 In. Women as a German Skater. As of 2023, O'Neill is producing a film titled Burn Down the Night based on the book of the same name by Craig Strete published in 1982. The film also has producers Andre Relis and Orian Williams attached to it. The plot will follow the life of Jim Morrison before he joined The Doors.