Party rooms were exclusive rooms that were only available for the duration of a party, although there were some that appeared directly before or after a party. Some were only accessible by members. All party rooms in Club Penguin used a .swf named "partyX", where X represented a number from 1 through 27. New party rooms overwrote older ones.
The first party room to appear in Club Penguin was the Treetop Fort, which appeared as a party room at the Medieval Party 2008. Since then, many parties have used these rooms. The last new party room to appear was the Reef at the Finding Dory Party, and the last party room to appear, overall, was Santa's Sled during the Holiday Party 2016.
- Although not common, some pins have been hidden or obtainable in party rooms, only available during the duration of the party the room appeared in.
- The parties with the most party rooms were the Medieval Party 2012 and Prehistoric Party 2016 (when combined with Operation: Crustacean), with each having a total of 27 party rooms. Prior to the former, the Medieval Party 2011 had the most, with 23.
- The Stadium, Cave Mine, Hidden Lake, Underwater room, and Mall all first appeared as party rooms before becoming normal rooms.