At the age of 11, she was chosen by a casting director from among hundreds of girls at her primary school in Mt. Wellington to play the memorable role of Paikea in Whale Rider (2002). Despite her lack of previous acting experience, Castle-Hughes received an Oscar nomination for Best Actress, making her -- at 13 years old -- the youngest actress ever to be nominated in this category.
In 2004, George Lucas cast Castle-Hughes to play the new Queen of Naboo in Star Wars: Episode III: Revenge of the Sith (2005).
In the third and final installment of George Lucas's Star Wars prequel trilogy, Anakin Skywalker (Hayden Christensen) and Padmé Amidala (Natalie Portman) are married, and General Grievous leads the Confederacy in a battle against the Republic. Meanwhile, Darth Sidious (Ian McDiarmid) is luring war-weary Anakin to the dark side, forcing Obi-Wan Kenobi (Ewan McGregor) to fight against his former pupil. Samuel L. Jackson and Jimmy Smits co-star.