North America's first two-screen theatre, The Elgin Theatre was created in 1957 by Nat Taylor in Ottawa, Canada when he expanded the 20 year old facility. Taylor is credited as inventor of the multiplex or cineplex, and later founded the Cineplex Odeon Corporation, openning the 18-screen Toronto Eaton Centre Cineplex, the World's largest at the time.

Stanley Durwood of American Multi-Cinema i.e now AMC Theatres pioneered what would become the multiplex in 1963 after realizing that he could operate several attached auditoriums with the same staff needed for one through careful management of the start times for each movie.

A popular movie may be shown on multiple screens at the same multiplex, which reduces the choice of movies but offers more choice of viewing times or a greater number of seats to accommodate patrons. Two or three screens may be created by dividing up an existing cinema but newly built multiplexes usually have at least six to eight screens, and often as many as twelve, fourteen or even sixteen. In these large modern theaters, an electronic display in the ticket hall often shows a list of movies with starting time, auditorium number, admission rating, and whether it is sold out.

Sometimes the number of remaining available seats is shown as well. At the entrance of each auditorium there may be a one-line electronic display with the title of the movie. After the movie has started, it can display the title and time of the next scheduled showing.

Although definitions vary, a large multiplex with 18 or more screens is usually called a megaplex. The first megaplex is generally considered to be the Kinepolis in Brussels, Belgium, which opened in 1988 with 25 screens and a seating capacity of 7,500. The first megaplex in the United States was the AMC Grand 24 in Dallas, Texas, which opened on May 19, 1995.