Stars have shown their support for World Water Day.

Celebrities including Gwyneth Paltrow, Jessie J and Beyonce have taken to social media sites to help promote charity Drop4Drop's efforts to provide clean water for everyone.

'Iron Man' actress Gwyneth posted a make-up free selfie on Instagram of her drinking from a bottle of water, captioning the image, ''full of healing power. #iLoveWater #WorldWaterday@drop4drop''.

Jessie J rallied her fans to the cause, reminding them to appreciate their easy access to water and asking them to donate.

She wrote alongside an image of her sipping from a glass of water: ''Don't take water for granted! I love water! This #WorldWaterDay let's make a difference! #iLoveWater @drop4drop''.

Lily Allen and Example have also shared their love for H2O with Instagram selfies, while the charity reposted a message from Beyonce's official Facebook page, thanking the superstar for drawing people's attention to their campaign.

World Water Day, which has been observed on 22 March since 1993, aims to promote awareness of the critical water issues facing our generation and raise money for the 800 million people in third world countries who risk their lives by drinking and using dirty water.