Pajama party may refer to:

• A sleepover
• Pajama Party (film), a 1964 film
• Pajama Party (group), a 1980s and 1990s R&B trio
• Pajama Party (TV series), a television talk show series
• "Pajama Party" (Pee-wee's Playhouse), an episode of Pee-wee's Playhouse

• BiP (artist)
• Bipartite graphs
• Bipasha Basu filmography
• BIP (brewery)
• Bipennate muscles
• Bipes alvarezi
• Bipes canaliculatus
• Bipes (genus)
• Bipes tridactylus
• BIPHA
• Biphase-H
• Biphase-H code
• Biphase-H coding
• Biphase-H encoding
• Biphase-H Manchester code
• Biphase-H Manchester coding
• Biphase-H Manchester encoding
• Biphase-L
• Biphase-L code
• Biphase-L coding
• Biphase-L encoding
• Biphase-L Manchester code
• Biphase-L Manchester coding
• Biphase-L Manchester encoding
• Biphasic or polyphasic sleep