Who played Jack Donaghy on 30 Rock?

Alec Baldwin played Jack Donaghy on 30 Rock. Jack is the powerful NBC network executive who becomes Liz Lemon's boss, mentor, antagonist, and eventually one of her closest allies.

The character first arrives as a senior executive overseeing East Coast television programming for General Electric, the corporate owner of NBC in the show's early seasons. Jack is intensely focused on ratings, corporate power, and career advancement, but he also takes a personal interest in keeping Liz effective as TGS's head writer.

Baldwin's performance made Jack's exaggerated confidence and executive-speak central to the show's comic style. Jack's rivalry with Tracy Jordan and his attempts to control the TGS production often turn ordinary television decisions into elaborate corporate battles.

The character is fictional, although his role reflects the real relationship between NBC's corporate leadership and the network's entertainment divisions. Another common mix-up is identifying Jack as the show's producer or star: he is primarily the network executive overseeing the program, while Liz runs its writing operation.