Cristofer was born Michael Procaccino in Trenton, New Jersey, the son of Mary and Joseph Peter Procaccino. He started his theatrical career as an actor, primarily on stage. He also started writing plays. He has also written numerous screenplays for film. Cristofer was awarded a Pulitzer Prize for Drama and a Tony Award for the Broadway production of his play, The Shadow Box. After New York City, the play was produced in every major American city and worldwide from Europe to the Far East. Other plays include Breaking Up at Primary Stages; Ice at Manhattan Theatre Club; Black Angel at Circle Repertory Company; The Lady and the Clarinet, produced by the Mark Taper Forum, Long Wharf Theater, Off-Broadway and on the London Fringe; and Amazing Grace, which received the American Theater Critics Award as the best play produced in the United States during the 1996–97 season. Cristofer's film work includes the screenplays for The Shadow Box, directed by Paul Newman ; Falling in Love; The Witches of Eastwick, adapted from the novel by John Updike; The Bonfire of the Vanities, adapted from the novel by Tom Wolfe and directed by Brian De Palma; Breaking Up, and Casanova. His directing credits include Gia, for HBO Pictures, which was nominated for five Emmy Awards and for which he won a Directors Guild Award. He next directed Body Shots; and Original Sin, which was released in 2001. For eight years he worked as artistic advisor and finally co-artistic director of River Arts Repertory in Woodstock, New York, a company which produced new plays by writers such as Richard Nelson, Mac Wellman, Eric Overmeyer, and others, including the American premiere of Edward Albee's Three Tall Women, a production which later moved to Off-Broadway. Also at River Arts, he wrote stage adaptations of the films Love Me or Leave Me and the legendary Casablanca. He directed Joanne Woodward in his own adaptation of Henrik Ibsen's Ghosts. His most recent work for the theater, The Whore and Mr. Moore, premiered at Dorset Theatre Festival's 2012 summer season. He collaborated with trumpeter Terence Blanchard, writing the libretto for Champion, a boxing opera in jazz music based on the life of prize fighter Emile Griffith. It premiered in June 2013 at Opera Theater of St. Louis. His latest work, Execution of the Caregiver, is based on the true story of a woman in South Carolina who killed her mother, fiancé and several people for whom she was purportedly caring. After a 15-year hiatus, Cristofer returned to his acting career, appearing in Romeo and Juliet, Trumpery by Peter Parnell, Three Sisters, Body of Water, and the Broadway revival of A View from the Bridge. He recently appeared in The Other Woman, and created the role of Gus in Tony Kushner's The Intelligent Homosexual's Guide to Capitalism and Socialism with a Key to the Scriptures at the Public Theater. In 2010, Cristofer was a cast member on AMC's Rubicon, in which he played Truxton Spangler. In 2012, he played Jerry Rand on the NBC series, Smash, husband to Anjelica Huston's character, Eileen Rand. In 2013–14, he played millionaire witch-hunter Harrison Renard in . In 2015, Cristofer made guest appearances in four episodes of season one of Mr. Robot as Phillip Price, the shadowy CEO of the sinister E Corp, and went on to be promoted as a cast member in season two, three, and four.
