Born in Norwalk, Connecticut, grew up in New Jersey, Bart made his Broadway debut in Big River as Tom Sawyer in 1987. Additional theatre credits include Jonathan in the Alan Menken/Tim Rice musical King David, Harlequin in Triumph of Love, Snoopy in the Broadway revival of You're A Good Man, Charlie Brown (for which he won the Drama Desk Award and a Tony), Carmen Ghia and later Leo Bloom in The Producers (earning Drama Desk and Tony nominations), and The Frogs at Lincoln Center, which reunited him with fellow Producers star Nathan Lane.

On television Bart played George Carlin's son on The George Carlin Show (1994), and on Bram and Alice (2002) he portrayed Bram's assistant Paul Newman. He became widely known to viewers with his portrayal of George, the murderous pharmacist in love with Bree Van De Kamp (Marcia Cross), on Desperate Housewives.

Bart provided the singing voice for Hercules in Disney's Hercules, as well as the singing voice of Scamp in Lady and the Tramp II: Scamp's Adventure. He was featured in the 2004 remake of The Stepford Wives with Nicole Kidman, Matthew Broderick, Bette Midler, Christopher Walken and Glenn Close, and in The Producers (2005), in which he reprised his role of "common-law assistant" Carmen Ghia.

In December 2006, Bart played Howard "The Weasel" Montague in the Sci Fi Channel miniseries The Lost Room. In June 2007, he stared in Hostel: Part II, the sequel to 2006's Hostel, and in November, he will appear in American Gangster, also in sometime 2007, portray Principal Hampton in Doubting Thomas. In 2008, he will appear in Harold & Kumar 2, the sequel to 2004's Harold & Kumar Go to White Castle, and Midnight Meat Train.

Bart will originate the lead role of Dr. Frederick Frankenstein in the musical adaptation of Mel Brooks' Young Frankenstein which starts playing on Broadway in October 2007.

(2007- ) Young Frankenstein- Dr. Frankenstein

(2004) The Frogs- Xanthias (co-starring Nathan Lane and directed by Susan Stroman of The Producers)

(2001-2007) The Producers- Carmen Ghia (original)/ Leo Bloom (replacement) (Drama Desk & Tony Award nominations)

(1999) You're A Good Man, Charlie Brown- Snoopy (Drama Desk & Tony Award wins)

(1997-1998) Triumph of Love- Harlequin

(1997) King David- Jonathan

(1987) Big River- Tom Sawyer (replacemant)- Debut

Preceded by

Ron Rifkin

for Cabaret

Tony Award for Best Featured Actor in a Musical

for You're a Good Man, Charlie Brown

Succeeded by

Boyd Gaines

for Contact