Highmore began his acting career with small roles on television at the age of 7. He made his film debut in Coky Giedroyc's comedy "Women Talking Dirty" (1999), playing the son of a woman (Helena Bonham Carter) who has recently become estranged from her commitment-phobic French lover. In 2001, Highmore played a young King Arthur in the TNT miniseries "The Mists of Avalon", a take on the Arthurian legends that depicted the women of Camelot as the real power behind the throne.