Ryan, best known for her role as Amelia Hetebrink in the NBC series "Amen," has been a longtime Chicago fixture, having played "Mama" on Broadway and on numerous national and international tours since the late '90s. She succeeds LaVon Fisher-Wilson, who concluded her run Feb. 27.

The Broadway company of Chicago currently stars Bianca Marroquin as Roxie Hart, Leigh Zimmerman as Velma Kelly, Raymond Bokhour as Amos Hart and Brent Barrett as Billy Flynn. (As previously announced, two-time Tony nominee Christopher Sieber will step into the role of Billy Flynn for a limited engagement beginning March 8 and continuing through March 25, and supermodel Christie Brinkley is set to make her Broadway debut as Roxie Hart for an 11-week engagement beginning April 4.)

Roz Ryan made her Broadway debut in the Fats Waller revue Ain't Misbehavin'. She also starred on The Great White Way in Dreamgirls and One Mo' Time and in the national tours of Annie, South Pacific and Blues in the Night. Ryan's film credits include "Went to Coney Island," "Cotton Club" and "Dark Indigo."

The revival of Chicago began life as one of the three annual Encores! presentations offered by City Center. The musical opened on Broadway at the Richard Rodgers Theatre in November 1996 where it remained through February 1997. The musical transferred to the Shubert Theatre on Feb. 11, 1997, and played that house through Jan. 26, 2003. The revival reopened at the Ambassador Theatre, its current home, on Jan. 29, 2003.

Chicago won the Tony Award for Best Revival of a Musical in 1997 as well as awards for actors Bebe Neuwirth and James Naughton, director Walter Bobbie, lighting designer Ken Billington and choreographer Ann Reinking. The original production was directed and choreographed by the late Bob Fosse. The Ambassador Theatre is located at 219 West 49th Street. Visit www.ChicagoTheMusical.com for more information.