If you didn't know that Dec. 14 was National Monkey Day, then you've been missing out on years of fun celebrations, but never fear, we're here to help you make up for lost time with celebrity friends such as Jimmy Fallon, Paris Hilton and Beyoncé.
As its name suggests, the celebrations are mainly monkey focused, but they do extend to other primates such as apes, tarsiers and lemurs. The unofficial holiday was started in 2000 and now inspires costume parties, movie marathons (think Planet of the Apes, King Kong and Monkey Kingdom) and general monkey behaviour. A number of zoos also hold themed events and many of the celebrations are designed to raise money and awareness for monkey- and animal-related causes.
To get you feeling festive this monkey season we've rounded up some of our favourite photos of famous faces, young and old, palling around with adorable primates. From Justin Bieber to Johnny Carson, everyone's got a monkey photo to share, and you're going to want to see them all!
Whether you're "oohing" and "ahhing" because you can't get enough of these precious faces or because you've caught the holiday spirit and fancy yourself a monkey for a day, this gallery is guaranteed to be more fun that a barrel of monkeys!