Lillian Müller (born 19 August 1951 in Grimstad, Norway) is a Norwegian model and an actress in motion pictures and television. A 5 times "Page Three Girl" with her first appearance in January 1974, Müller achieved her major breakthrough after being spotted by Suze Randall, who photographed her Playboy cover and pictures in her Playmate pictorial (centerfold photographed by Dwight Hooker). Müller appeared in the magazine as Playmate of the Month in August 1975, and was subsequently named Playmate of the Year in 1976.
Müller also appeared in Van Halen's "Hot for Teacher" video as the chemistry teacher. In 1978, she portrayed Rod Stewart's love interest in his video "Da Ya Think I'm Sexy?"
She is sometimes credited as Inga Anderssen, Lillian Mueller, Yulis Revel, Yuliis Ruval, or Yullis Ruval.