Anniversary Parties are parties held to celebrate the anniversary of Club Penguin. Except for the 10th Anniversary Party, they all occur during October 24, the date when Club Penguin was officially launched in 2005. They are held at the Coffee Shop and they give out a free Party Hat.
- 1st Anniversary Party (2006)
- 2nd Anniversary Party (2007)
- 3rd Anniversary Party (2008)
- 4th Anniversary Party (2009)
- 5th Anniversary Party (2010)
- 6th Anniversary Party (2011)
- 7th Anniversary Party (2012)
- 8th Anniversary Party (2013)
- 9th Anniversary Party (2014)
- 10th Anniversary Party (2015)
- 11th Anniversary Party (2016)
- Main article: Party Hats
- Main article: Anniversary Cakes
Each Anniversary Party has its own unique anniversary cake, that matches the party's theme color. The size of the cakes varied with each party.
- Main article: Yearbook
Each year, during the yearly Anniversary Party, a new yearbook is released, which contained all the events from the last 12 months (October of previous year through September of current year). An exception is the Yearbook 2014-2015, which contained an overview of the entire history of Club Penguin up till its release date. The book also includes images of some of the hidden pins from that year, that are hidden in the yearbook's pages and are visible by clicking certain parts on pages. The Yearbook 2015-2016 was only readable during the 11th Anniversary Party.
- All anniversary parties since the 3rd Anniversary Party lasted more than 1 day. However, the 4th Year Party was only extended due to technical problems with the game that made penguins unable to get to the site or enter the Coffee Shop. Due to this, Club Penguin more than willingly extended the party an extra day. The 8th and 9th anniversaries are the only two to last an entire week.
- The 10th Anniversary Party was the biggest Anniversary Party. There were 30 decorated rooms and everyone could get a free item every day from the 10th Anniversary Item Calendar. In the Coffee Shop there was a huge cake with candles on it. You could blow them by clicking on them.
- The 11th Anniversary Party was the last Anniversary Party in Club Penguin, since the game closed on March 29, 2017.