This refers to the theatrical slang term, for other uses see Blockbuster (disambiguation)

Blockbuster is a term derived from theater slang referring to a particularly successful play (i.e. one that is so successful that competing theaters on the block are "busted" and driven out of business). However another more popular explanation is that the term was first derived from the crowds of people that flocked to queue up for George Lucas' Star Wars in May 1977, and who gathered over several city blocks, hence the term came into existence.

The term can apply to other productions besides plays (which are rarely successful and often lose money), such as musicals, movies and novels and multimillion selling computer/console game titles. The motion picture industry in particular has adopted the term for a financially successful film. In a looser sense, it may mean any big-budget Hollywood movie with famous stars that dominates public attention, even if the movie is a dud.

The threshold for a blockbuster in North America has often been placed at $100 million in ticket sales, a mark first achieved by Steven Spielberg's Jaws. However, because of steady increases in ticket prices since the release of Jaws in 1975, the threshold for a blockbuster in the early 21st century is now generally set at $200 million.

However, when a film made on a low budget is particularly successful, especially one of an atypical variety like the Blair Witch Project (amateur-produced first person narrative film), Crouching Tiger, Hidden Dragon (non-English language foreign film) and Fahrenheit 9/11 (political documentary film), all of which have made over $100 million each, then those films are considered blockbusters as well on account of spectacularly surpassing the industry's expectations.

As Hollywood has focused on creating films with the broad appeal necessary to achieve high ticket sales, it has been criticized for succumbing to a "blockbuster mentality", to the detriment of artistic quality.