Earned a degree in finance from Georgetown University and worked as a litigation consultant in Florida before switching careers.
Performed first stand-up routine in 1991, and then spent four years scripting commercials and studying acting.
First appearance on David Letterman's show garnered Gaffigan acclaim and an offer to develop the sitcom Welcome to New York, which was canceled after three months.
Has appeared in more than 200 commercials, including campaigns for Saturn, ESPNews, Energizer, Barnes & Noble.com, Kodak and Rolling Rock. His commanding presence in commercials earned him the title "Salesman of the Year" by Business Week in 1999.