Phoebe Jane Elizabeth Tonkin (born 12 July 1989) is an Australian actress and model. She is best known for portraying Cleo Sartori in H2O: Just Add Water, Fiona Maxwell in Tomorrow, When the War Began, and Faye Chamberlain in The Secret Circle. In December 2005, Tonkin was cast as the role of Cleo Sartori on the Australian children television series H2O: Just Add Water which follows the lives of three teenage girls who turn into mermaids. Tonkin improved on her swimming abilities during the pre-production of the series. The series premiered on 7 July 2006 on Network Ten and has since gone on to be aired to a worldwide audience of more than 250 million. To promote the series she and her co-stars presented the best band award at the Nickelodeon UK Kids' Choice Awards in October 2007. In 2008, Tonkin was nominated for "Best Lead Actress in a Television Series" at the prestigious Australian Film Institute Awards. The series ran for three seasons with the series finale airing on 16 April 2010.
Tonkin has also appeared on fellow Australian television shows Packed to the Rafters and Home and Away. In September 2010, Tonkin made her film debut starring in the Australian action ensemble film Tomorrow, When the War Began. In the film, which revolves around a group of teenagers waging a guerrilla war against an invading foreign power in their fictional hometown of Wirrawee, she played the role of the rich and uptight Fiona Maxwell. In December 2010, a sequel was announced with Tonkin expected to return.
In January 2011, Tonkin moved to Los Angeles to pursue an international acting career. She was cast in March 2011 as Faye Chamberlain on The CW supernatural drama series The Secret Circle which premiered on 15 September 2011 to over 3.5 million viewers. The series follows a group of young witches whom are a part of a secret coven. Tonkin has received acclaim from critics being referred to as the breakout star of the series; she was featured on Variety's list of "new faces to watch" and named one of 2011's breakout TV stars by E! Online. The Secret Circle, however, had only one full season as it was cancelled on 11 May 2012.
In August 2010, Tonkin was cast in the 3D horror film Bait. Filming took place on Australia's Gold Coast and follows a group of strangers who are trapped in a supermarket after a freak tsunami with a pack of great white sharks. The film is expected to be released in Australia in September 2012. In August 2012, Tonkin was reported as being cast in the TV series The Vampire Diaries in a recurring role as Hayley, a friend of Tyler, joining her co-star from H2O: Just Add Water, Claire Holt, who portrays Rebekah Mikaelson.