From other TV shows:
* "Seinfeld": Jerry Stiller (Arthur Spooner) was on "Seinfeld" as Frank Costanza.
* "Friends": Joey Tribbiani (Matt LeBlanc) appeared as himself in one episode.
* "Everybody Loves Raymond": Peter Boyle (Frank Barone) appeared as himself in one episode, playing Doug Heffernan's favorite comedian.
* "The Sopranos": Tony Sirico (Paulie Walnuts) made a guest appearance as himself, getting into a minor altercation with Doug.
* "The Nanny": Fran Drescher (Fran Fine) appeared as herself in one episode, getting into a humorous argument with Carrie about who was the better wife.
* "The Drew Carey Show": Drew Carey appeared as himself in one episode, playing a customer at Doug's delivery company.
Other notable guest stars:
* Bob Saget: Known for "Full House", he played a therapist in one episode.
* Jason Alexander: Known for "Seinfeld", he played a character named "Max" who Doug met in a bar.
* Kathy Griffin: Known for her stand-up comedy, she played a woman who had a one-night stand with Doug.
This is just a small sample. Many other actors and actresses appeared in guest roles on "The King of Queens". You can find full lists online with more details about their appearances.