TV Guide Online: It's a Mad, Mad, Mad, Mad World
- Includes a review, cast and crew credits, and awards.
- http://www.tvguide.com/movies/mad-mad-mad/102377

Rotten Tomatoes: It's a Mad, Mad, Mad, Mad World (1963)
- Reviews from critics and audiences, articles, synopsis, and cast and crew information.
- http://www.rottentomatoes.com/m/its_a_mad_mad_mad_mad_world/

POVonline: It's a Mad, Mad, Mad, Mad World
- Mark Evanier talks about this comedy classic, including pages on the big "W", running times of different versions, the 39th anniversary reissue, and a FAQ.
- http://www.povonline.com/MadWorld.htm

Imperial Webpages: It's a Mad, Mad, Mad, Mad World
- A collection of film clips focusing on the use of a 1962 Chrysler Imperial convertible in the movie.
- http://www.imperialclub.com/Movies/Mad/index.htm

IMDb: It's a Mad Mad Mad Mad World (1963)
- Cast and credits, user ratings, and plot synopsis.
- http://us.imdb.com/title/tt0057193/

"It's A Mad, Mad, Mad, Mad World" at the Villa
- Information on the film's opening at the Villa Theatre in Salt Lake City, Utah on Wednesday, 19 February 1964. Includes newspaper ads and articles about the event.
- http://villatheatre.com/history/1964/MadIndex.html

Mutant Reviewers from Hell do "It's A Mad, Mad, Mad, Mad World"
- Provides a review with quotes and trivia about the movie.
- http://www.mutantreviewers.com/rmadworld.html

HomeVideos.com: It's A Mad, Mad, Mad, Mad World
- Provides a review and recommendations of similar movie.
- http://www.homevideos.com/revcom/21b.htm

PizzaBagel: It's a Mad, Mad, Mad, Mad World
- Features personal observations, quotes, and links.
- http://pages.prodigy.net/pizzabagel/M4W.htm

Nitpickers: It's a Mad Mad Mad Mad World - 1963
- A list of glitches and continuity mistakes.
- http://www.nitpickers.com/movies/titles/45693.html

Yahoo! Movies: It's a Mad, Mad, Mad, Mad World (1963)
- Cast and credits, user ratings and reviews, and plot synopsis.
- http://movies.yahoo.com/shop?d=hv&cf=info&id=1800082067