Miller left her native Los Angeles, when she was age 18, and moved to New York, where she studied acting at HB Studios under Herbert Berghof. Two years later, Miller got her big break on Broadway, when she originated the role of "Daisy Hanningan" in Neil Simon's Tony Award-winning play, "Biloxi Blues". Later, she would reprise her role in Universal's film version, directed by Mike Nichols.
Her career most recently includes the 2012 Academy award Best Picture winner, The Artist (2011), co-starring opposite Best Actor winner, Jean Dujardin, directed by Michel Hazanavicius, who also won Best Director that year and was released by The Weinstein Co. Penelope has shared the screen with some of the most notable and renowned leading men and directors in Hollywood and around the world. This impressive list includes Al Pacino and Sean Penn in director Brian De Palma's L'impasse (1993), for which she received a Golden Globe nomination; Marlon Brando and Matthew Broderick in Premiers pas dans la Mafia (1990), directed by Andrew Bergman; Robert De Niro and Robin Williams in Penny Marshall's L'éveil (1990); Robert Downey Jr. in Sir Richard Attenborough's Chaplin (1992); The Shadow (1994) with Alec Baldwin, Danny DeVito and Gregory Peck in Norman Jewison's Larry le liquidateur (1991); Matthew Broderick and Christopher Walken in Mike Nichols' Biloxi Blues (1988); and Arnold Schwarzenegger in Ivan Reitman's Un flic à la maternelle (1990) and she starred in Rob Reiner's, film Flipped (2010), for which he wrote and directed for Warner Bros. She was last seen in ABC's hot new show ,Mistresses ,(2013/14), and in the critically acclaimed, Men Of A certain Age, opposite, Ray Romano( 2009/10/2011)
Miller's credits also include Sony Pictures' box office hit, Les messagers (2007), which opened #1. The supernatural thriller was produced by Sam Raimi. Miller starred opposite Kristen Stewart (The Twilight Saga), John Corbett and Dylan McDermott. She also starred in Think Films' slapstick comedy, Funny Money (2006), opposite Chevy Chase, in which her performance was compared to Lucille Ball and Carole Lombard in their heydays.
Miller was named "Star of Tomorrow" by the Motion Picture Bookers Club and "Most Promising Actress" by the Chicago Film Critics Association. She received a special jury award for Best Performance at the Hollywood Film Festival for her role in the independent feature, Rhapsody in Bloom (1998), and a Tony Award nomination for her portrayal of "Emily" in Broadway's Tony-winning revival of "Our Town". Miller's television credits include Rocky Marciano (1999), opposite Jon Favreau and George C. Scott; Le dernier parrain (1997), opposite Joe Mantegna; All-American Girl: The Mary Kay Letourneau Story (2000), for which she won critical acclaim, and Rudy: The Rudy Giuliani Story (2003), opposite James Woods.
Miller lives in Los Angeles with her husband and two daughters.