Mackenzie Phillips, born Laura Mackenzie Phillips on November 10, 1959, is an American actress, singer, and author. She is best known for her roles in the film "American Graffiti" as Carol Morrison, the television sitcom "One Day at a Time" as Julie Cooper Horvath, the Disney Channel series "So Weird" as Molly Phillips, and the Netflix series "Orange Is the New Black" as Barbara "Barb" Denning.

Her father, John Phillips, was a founding member of the famous folk-rock group The Mamas & the Papas, which influenced her early exposure to music and entertainment.

Mackenzie Phillips attended Highland Hall Waldorf School in Northridge, California, where she formed a band with classmates at the age of 12. A talent scout spotted her during one of their performances, leading to her casting in "American Graffiti" at the age of 12.

Her breakout role came in the hit CBS sitcom "One Day at a Time," where she portrayed Julie Cooper, a rebellious teenager. Despite her success, she struggled with substance abuse, which led to her departure from the show in 1980. She entered rehab multiple times and eventually returned to acting.

Mackenzie Phillips also performed as a singer and toured with a re-formed version of The Mamas & the Papas, known as The New Mamas and The Papas, from the mid-1980s to the early 1990s.

She co-starred with Cara DeLizia in the Disney Channel series "So Weird" from 1999 to 2001, playing a fictional rock star named Molly Phillips. She has also appeared in guest roles on various television shows and continues to work in the entertainment industry.

She released her memoirs, "High on Arrival," in which she revealed her relationship with her father as a consensual sexual relationship. This revelation brought her into the spotlight for a different reason, and she has since been open about her struggles and recovery. She has a net worth of over $1 million and remains a celebrated name in Hollywood.

Throughout her career, she has received several awards and nominations, including the LA Femme International Film Festival Meritorious Achievement Award in 2012.