Stewart's big break came with landing the role of Casey Bowman, a man with a troubled father, on the soap opera Loving. While portraying Casey by day, Stewart landed the starring role of Christian in the 1993 production of "Cyrano: The Musical" on Broadway at the Neil Simon Theatre. A couple years after leaving "Loving" and the closing of "Cyrano", Stewart once again landed a role on a daytime soap opera role. This time he was to portray Danny Santos of the famous Santos Mob family in "Guiding Light". The first appearance of Danny was November 11, 1998 and was an instant success with viewers. In 2003 Stewart earned a Daytime Emmy Award Nomination for Outstanding Supporting Actor. Stewart once again took to The Great White Way by night while performing in a daytime drama. This time in the 2003 Revival of "Fiddler on the Roof" at the Minskoff Theatre replacing Robert Petkoff as the progressive student Perchik. On November 22, 2005, Stewart made his departure as Danny from "Guiding Light" only to return a few years later. Due to the show's cancellation in 2009 Stewart reprised his role as Danny Santos from July 2, 2009 to September 18, 2009 in order to bid adieu to the series forever.

Since his departure from the soap opera realm, Stewart has been proven a mainstay in the American theatre. His most recent Broadway appearance was as Jerzy in the short-lived 2011 production of "The People in the Picture" at Studio 54. Off-Broadway, Stewart completed a limited run of "Harbor" at 59E59 Theater in September 2013. In addition, John Kanders new work "The Landing" stars Stewart along with Julia Murney, David Hyde Pierce, and Frankie Seratch Off-Broadway at the Vineyard Theatre ending November 24, 2013.