Quokkas get their very own birthday

It already has its own hashtag, and now WA's most loveable animal - the Quokka - is getting its own day of celebration.

The furry critters have melted hearts across the world and sent social media into a spin with the obligatory Rottnest Island "quokka selfie".

Roger Federer, Chris Hemsworth and Margot Robbie and are among the A-list celebrities who've helped fuel the marsupial's internet fame, putting Western Australia in the global spotlight.

The quokka's cuteness and willingness to pose for photos has even seen it labelled the "World's Happiest Animal".

To cash in on its star power, the State Government is throwing the Rottnest icon a birthday party from September 13-15, offering free travel to the island for children under 12.

There will also be cheaper ferry tickets for adults and discounts on accommodation.

The quokka's birthday will be celebrated every year in September, which is the best time to see joeys in their mum's pouch.