A box-office bomb is a film that is unprofitable or considered highly unsuccessful during its theatrical run. Any film for which the combined production budget, marketing, and distribution costs exceed the revenue after release is often considered a commercial failure, but the terms "bomb" or "flop" are most frequently used for major studio releases that were highly anticipated, extensively marketed, and expensive to produce, but nevertheless failed commercially.

A film can fail at the box office for a variety of reasons, including