A public domain film is a film that was released to public domain by its author or because its copyright has expired.

Many pre-1954 Japanese films have passed into public domain in Japan.^{[dead link][dead link]} See Japanese Films copyright timeline.

Due to the U.S. Copyright Term Extension Act, no more films will automatically enter public domain in the United States until January 1, 2019, when the copyright will expire on films released in 1923 (and in 2020 films from 1924, and so on).

Another issue specific to the U.S. nonetheless impacts world copyright. The Uruguay Round agreements on copyright led to the U.S. Congress re-imposing copyright on some items which had fallen into the public domain (in section 514 of the URAA Act), as of 1996.

In the course of changes made to both U.S. domestic law and international copyright agreements in the last two decades, some works which had fallen in the public domain had copyright restored in the U.S. This was challenged on the grounds that works once in the public domain could not revert to copyright protection - a constitutional question. The see-saw course of court decisions on the matter have caused confusion, with many significant works (such as The Third Man) changing status several times in a short period.

The public domain refers to works whose intellectual property rights have expired, been forfeited, or are inapplicable. Examples include the works of Shakespeare and Beethoven, most of the early silent films, the formulae of Newtonian physics, and the patents on powered flight. The term is not normally applied to situations when the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or with permission.

Informally, public domain refers to works that are publicly available; the formal definition states that it refers to works which are intangible to private ownership or are available for public use. As rights are country-based and vary, a work may be subject to rights in one country and not in another. Some rights depend on registrations with a country-by-country basis, and the absence of registration in a particular country implies public domain status there.

Public domain did not come to fruition as a term until the mid-17th century, although as a concept "it can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be privately owned" as res communes, res publicae and res universitatis. The term res commune was defined as "things that could be commonly enjoyed by mankind, such as air, sunlight and ocean." The term res publicae referred to things that were shared by all citizens, and the term res universitatis meant things that were owned by the municipalities of Rome. When looking at public domain from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res commune, res publicae, and res universitatis in early Roman Law.

Bugs Bunny is an American animated character created in 1938 at Leon Schlesinger Productions, later Warner Bros. Cartoons. Bugs is an anthropomorphic gray hare or rabbit and is famous for his flippant, insouciant personality, a pronounced Brooklyn accent, and his portrayal as a trickster. He has primarily appeared in animated cartoons, most notably the Looney Tunes and Merrie Melodies series of theatrical short films. His popularity there led to his becoming a corporate mascot of the Warner Bros. company. Bugs has appeared in more films than any other cartoon character and is the ninth most portrayed film personality in the world.

According to Bugs Bunny: 50 Years and Only One Grey Hare, Bugs was born on July 27, 1940 in Brooklyn, New York in a warren under Ebbets Field, home of the Brooklyn Dodgers. In reality, he was created by many animators and staff, including Tex Avery, who directed A Wild Hare, Bugs' debut role, and Robert McKimson, who created the definitive "Bugs Bunny" character design. According to Mel Blanc, the character's original voice actor, Bugs has a Flatbush accent. Bugs has had numerous catchphrases, the most prominent being a casual "Eh... What's up, doc?", usually said while chewing a carrot.