Allison Janney Gets Birthday Surprise at Broadway's ON THE TOWN

Allison Janney thought she would quietly celebrate her 55th birthday by enjoying a performance of Broadway's On The Town last night, but the former "West Wing" star wound up getting a much bigger celebration than she planned on.

According to The New York Post, the entire cast of the new Broadway revival serenaded the 'Mom' star at the top of Act Two by singing a rousing rendition of 'Happy Birthday.' In every performance, the cast singles out an audience member or military vet who is celebrating their birthday as part of a nightclub scene.

The special performance made the Tony nominee's birthday one that she will surely never forget.

With multiple Tony and Golden Globe nominations, an Outer Critics Circle Award, Drama Desk Award, 6 Screen Actors Guild Awards, and 4 Emmys, Ms. Janney currently stars in the new CBS/Chuck Lorre sitcom, "Mom," opposite Anna Faris. She also appears in a multi-episode arc on the groundbreaking Showtime drama "Masters of Sex."

Her feature, The Way, Way Back with Steve Carell and Toni Collette, is currently in theaters. In addition, Janney has a number of films due for release, including Lynn Shelton's Touchy Feely, the Untitled Christian Camargo project with William Hurt and Jean Reno, the Untitled Marc Lawrence/Castle Rock project with Hugh Grant, Trust Me for director/actor Clark Gregg, and Jason Bateman's comedy Bad Words. Her other film credits include: The Help; Juno; Hairspray; Life During Wartime; Sam Mendes' Away We Go; The Hours opposite Meryl Streep; Academy Award winner American Beauty; and voicework in Finding Nemo. On television, Allison won four Emmy Awards for her performance as CJ Cregg on Aaron Sorkin's "The West Wing."

On stage, she made her Broadway debut in Noel Coward's Present Laughter. She also appeared in Arthur Miller's A View from the Bridge, receiving her first Tony Award nomination, and was last seen on Broadway in the musical 9 to 5, for which she earned a Tony Award nomination and won the Drama Desk Award.

The new Broadway revival of On The Town, directed by John Rando (Tony Award for Urinetown) and choreographed by Joshua Bergasse (Emmy Award winner for "Smash") officially opened October 16, 2014 at Broadway's Lyric Theatre.

The cast is led by Tony Yazbeck (Gypsy, A Chorus Line), Jay Armstrong Johnson (The New York Philharmonic's Sweeney Todd, Hands On A Hardbody, Hair), and Clyde Alves (Bullets Over Broadway, Nice Work If You Can Get It) as the sailors on 24-hour shore leave who take on the Big Apple; Megan Fairchild (New York City Ballet Principal Dancer), Alysha Umphress (American Idiot) and Elizabeth Stanley(Company) as the women who steal their hearts; and Jackie Hoffman (Hairspray, Xanadu) in the role of "Madame Dilly". Tony Award winner Michael Rupert (Legally Blonde: The Musical, Ragtime, Falsettos, Sweet Charity) plays "Judge Pitkin" alongside Allison Guinn (Hair) as "Lucy Schmeeler", Tony Award nominee Phillip Boykin (The Gershwins' Porgy and Bess) and Stephen DeRosa(Hairspray, The Nance, Into The Woods).