E! online initially reported that Jackson is joining the cast as a "permanent or semi-permanent player." It is not yet known to what extent he will appear on the show, but he joins a long list of Broadway actors who have been featured on the hit program.
Theatre folk previously seen on "30 Rock" include Patti LuPone, Deirdre Goodwin, Anita Gillette, Elaine Stritch, Nathan Lane, Brian Murray, John Lithgow, Edie Falco, Matthew Broderick, Roger Bart, Phoebe Strole and Kerry Butler.
The show, nominated for a record 22 Emmys in 2009, is created by Tina Fey. Joining Fey in the regular ensemble cast are Tony nominee Alec Baldwin, Tony winner Jane Krakowski, Tracy Morgan, Jack McBrayer, Scott Adsit and Judah Friedlander.
Click the photo below for a gallery of shots from Jackson's "30 Rock" debut: