Jack Lipnick (Barton Fink) is the President of Capitol Pictures. Another fast talking Coen character, Lipnick is the stereotypical idea of what a big time Hollywood studio mogul would be. He is constantly running on his belief in his own ideas. Lipnick almost appears to be bipolar, in his extreme ups and downs. Lipnick is unaware and uncaring towards the artistic workers doing his bidding. He claims that he wants "that Barton Fink feeling," though he never specifies or possibly understands exactly what that entails.

Lipnick is the first to meet with Barton Fink to discuss Fink's new job of writing movie scripts for $1000 per week. Lipnick promises Fink that his only hesitation in Fink's new position is his writing ability. Lipnick therefore assigns Fink's first task a script for a wrestling movie about Wallace Beery.

Lipnick's next meeting with Fink follows Fink's mysterious evening waking up next to Audrey's dead body. Lipnick supports Fink in the meeting, surprising Fink, who then finds the motivation to begin writing again.

In Lipnick's final meeting with Fink, he furiously reproves Fink for writing a "fruity movie about suffering." Lipnick seems to be taking out other frustrations on Barton Fink though, as he is also perturbed by the fact that he has just been drafted into the Pacific Theatre of World War II holding the rank of Colonel. Lipnick tells Fink that he is to remain in L.A. Lipnick says that though Fink is still under contract with Capitol Pictures, the company will not produce any of his scripts so that Fink may be disparaged as a loser around the studio while Lipnick is in the way.

Lipnick is portrayed by Michael Lerner, and his depiction of the egotistical film producer reeled in an Academy Award nomination for Best Actor in a Supporting Role.