H 2 O: Just Add Water is an Australian television programme for children that is filmed on location at Sea World on the Gold Coast, with outdoor school scenes filmed at Somerset College. It first screened on Network Ten in Australia and is currently screening on the Disney Channel, Nickelodeon UK and other channels in over one hundred countries worldwide, with Nickelodeon in the United States premiering the series on March 14, 2008. The show's premise revolves around three teenage girls facing everyday teen problems with an added twist: they're mermaids with powers over water. The theme song "No Ordinary Girl" is performed by Ellie Henderson in Series 1 and by Kate Alexa in Series 2.

The series was nominated for the 2007 Logie Award for "Most Outstanding Children's Program", as well as a 2007 Nickelodeon UK Kids' Choice Award for "Best TV Show".

Although planned for only two seasons and a total of 52 episodes, executive producer Jonathan M. Shiff has confirmed a third series will be produced in 2008, saying that "there is lots of potential for a third season with normal teenagers who have super powers," and that open water filming may be an option in addition to the filming done at Sea World and the Broadwater.

When three normal teenage girls stumble upon a ancient cave they undergo a transformation that will change their lives forever. H20 - Just Add Water, sees three very different girls facing everyday teen problems with an added twist - they're mermaids with incredible powers over water. Written by Australian Television Information Archive