A diamond jubilee is a celebration of the 60th anniversary of a significant event related to a person or the 60th anniversary of an institutions founding. The term is also used for 75th anniversaries, although this usage is less common due to the human lifespan. The name "diamond" refers to the fact that diamonds are the hardest known substance, symbolizing the strength and durability of the event being celebrated.

Examples of diamond jubilees include the Diamond Jubilee of Queen Victoria, which celebrated her 60-year reign on 22 June 1897. The Diamond Jubilee of Elizabeth II, the Queen, was celebrated across the Commonwealth of Nations throughout 2012. Her platinum jubilee was marked in February 2022 and celebrated throughout the United Kingdom in June.

Diamond jubilees are celebrated in various ways, including events, tributes, and charitable foundations. For example, the Queen Elizabeth Diamond Jubilee Trust was set up as a charitable foundation with a mission to leave a lasting legacy across the Commonwealth. Other projects included the Queen Elizabeth Diamond Jubilee Wood and the issuing of commemorative medals.