Michelle Phillips, born Holly Michelle Gilliam on June 4, 1944, in Long Beach, California, is an American singer, songwriter, and actress. She rose to fame as one of the two female vocalists in the musical quartet the Mamas & the Papas in the mid-1960s. Her voice was described by Time magazine as the "purest soprano in pop music".

Michelle Phillips spent her early life in Los Angeles and Mexico City, raised by her widowed father after her mother passed away when she was five. While working as a model in San Francisco, she met and married John Phillips in 1962 and went on to co-found the vocal group the Mamas & the Papas in 1965.

The band rose to fame with their popular singles "California Dreamin'" and "Creeque Alley," both of which she co-wrote. They released five studio albums before their dissolution in 1970. While married to John Phillips, she gave birth to their daughter, singer Chynna Phillips. Michelle Phillips is the last surviving original member of the band.

After the breakup of the Mamas & the Papas and her divorce from John Phillips, she transitioned into acting, appearing in a supporting part in The Last Movie (1971) before being cast as Billie Frechette in the critically acclaimed crime biopic Dillinger (1973), for which she was nominated for a Golden Globe Award for Most Promising Newcomer.

In 1974, she had lead roles in two television films: the crime feature The Death Squad, and the teen drama The California Kid, in the latter of which she starred opposite Martin Sheen. She went on to appear in a number of films throughout the remainder of the 1970s, including Ken Russell's Valentino (1977), playing Natacha Rambova, and the thriller Bloodline (1979).

She released her only solo album, Victim of Romance, in 1977. Phillips's first film of the 1980s was the comedy The Man with Bogart's Face (1980). The next year she co-starred with Tom Skerritt in the nature-themed horror Savage Harvest (1981), followed by the television films Secrets of a Married Man (1984) and The Covenant (1985).

In 1987, she joined the series Knots Landing, portraying Anne Matheson, the mother of Paige Matheson (portrayed by Nicollette Sheridan), until the series's 1993 conclusion. She later had supporting roles in the comedy film Let It Ride (1989) and the psychological thriller Scissors (1991). In 1998, she was inducted into the Rock and Roll Hall of Fame as a member of the Mamas & the Papas.

Her personal life has been marked by several marriages and relationships. She was married to John Phillips from 1962 until their divorce in 1970, and they had one daughter together, Chynna Phillips. She later married Dennis Hopper in 1970, but their marriage lasted only eight days.

Her other marriages included Robert Burch (1978-1982) and Steven Zax, whom she was with until his death in 2017. Michelle Phillips has three children: Chynna Phillips, Austin Hines, and Aron Wilson.