› [C] the place in a theatre or cinema where you buy tickets: Tickets are $8 and are available only at the box office. › [U] money from ticket sales, used as a way of measuring the success of a performer, film, or public event: The documentary became a surprise box office hit. In 1934, he was voted the top box-office draw for the year by theater owners. The 28-year-old heavyweight champion represents big box office.