While turning 31 might not be the most significant of birthdays, for a certain wombat, it's a very important day.

Winnie the wombat, who is the oldest wombat in Australia, and possibly the world, celebrated her birthday on Saturday at the National Zoo.

The National Zoo and Aquarium's Dr Danielle Johinke hands Winnie the common wombat her favourite treat on her 31st birthday. Credit:Sitthixay Ditthavong

One of the zoo's main attractions, Winnie arrived in 1992.

Team leader of Australian native animals Danielle Johinke said Winnie had been one of the longest-serving residents at the zoo.