Pajama Party is a 1964 beach party film starring Tommy Kirk and Annette Funicello. This is the fourth in a series of seven beach films produced by American International Pictures. The other films in this series are Beach Party (1963), Muscle Beach Party (1964), Bikini Beach (1964), Beach Blanket Bingo (1965), How to Stuff a Wild Bikini (1965), Ski Party a one-off film with a brief beach scene at the end (1965) and The Ghost in the Invisible Bikini (1966).

This fourth entry has not always been considered a follow-up to the three films that preceded it. Several sources have noted, however, that while it is not a proper sequel, it is indeed a part of what is now termed AIP's ‘Beach Party series.’ Moreover, AIP marketed it as a sequel in its trailer, stating "The Bikini Beach Party Gang is Warming Up! – For the 'Party' that Takes Off – Where others Poop Out!" and "All the 'Beach Party' Fun ... in Pajamas!"

Additional links that tie this film to the others are the return of Eric von Zipper and his Rat Pack (who previously appeared in Beach Party and Bikini Beach) and the return of Candy Johnson as Candy for the fourth time in as many films.

Regulars Frankie Avalon, Don Rickles, Annette Funicello, Jody McCrea and Donna Loren all appear (albeit with character name changes – not the first time this happens in the series, nor the last); Susan Hart makes the first of three appearances in the AIP brand of the genre; Buster Keaton makes the first of four appearances, and Bobbi Shaw makes the first appearance of five (including Ski Party). In addition, several background players in this film (Patti Chandler, Mary Hughes, Johnny Fain, Mike Nader, Salli Sachse, Luree Holmes, Ronnie Dayton, Ed Garner, Ray Atkinson, Linda Benson, and Laura Nicholson) also appear in three or more films in the AIP brand of the genre.

The film is not to be confused with the 1963 novel Pajama Party about lesbian activities among college girls, which was banned on the grounds of obscenity.