I Capture the Castle is a 2003 British romantic comedy film directed by Tim Fywell. It is based on the 1948 novel of the same name by Dodie Smith, with the screenplay written by Heidi Thomas. The film was released in the UK on 9 May 2003.

Romola Garai played the lead role of Cassandra Mortmain alongside Bill Nighy, Rose Byrne and Tara Fitzgerald.

The film follows 17-year-old Cassandra Mortmain, and her eccentric family, struggling to survive in genteel poverty in a decaying English castle. The characters include her father, a writer who hasn't written anything in the 12 years since the spectacular success of his first novel; her older sister, Rose, who rails against their fate and hopes to marry for money; and their bohemian stepmother, Topaz, an ex-model still apt to sunbathe in the nude. The possibility of salvation seems to loom in the form of their wealthy American landlord, Simon Cotton, and his brother, Neil. Although Simon initially spurns her, Rose is determined to make him fall in love with her and succeeds. A wedding is arranged, and Cassandra appears to be left on the sidelines. Cassandra is confused by her feelings for not only the Cottons but also Stephen Colley, the handsome son of the Mortmains' former cook who acts as a handyman to the family and is deeply in love with Cassandra. But events spiral out of control, and before the summer ends, many expectations will have been overturned.

Parts of the film were shot in Laxey film studio on the Isle of Man. Manorbier Castle in Pembrokeshire, Wales, supplied exteriors for the castle, and Eltham Palace in London some interiors.^[1]

On the review aggregator website Rotten Tomatoes, 78% of 85 critics' reviews are positive, with an average rating of 6.7/10. The website's consensus reads: "A handsome and charming adaptation of the novel."^[2]