Warner Bros. Pictures' origins trace back to 1918, when brothers Harry, Albert, Sam, and Jack Warner established a studio on Sunset Boulevard. Sam and Jack would handle the production of the films, while Harry and Albert were in charge of distribution. The studio was incorporated as Warner Bros' Pictures Incorporated on April 4, 1923, making it the third oldest American movie studio in continuous operation, after Paramount Pictures (founded on May 8, 1912 as Famous Players Film Corporation) and Universal Pictures (founded on April 30, 1912). It is one of the "Big Five" studios, alongside Paramount Pictures, Sony Pictures (Columbia Pictures and TriStar Pictures), Universal Pictures, and the Walt Disney Studios.

After remaining independent for its first 45 years in operation, Warner Bros. was subject to numerous acquisitions over the decades. First, the studio merged with Seven Arts Productions to become Warner Bros.-Seven Arts in 1967. Two years later, the studio was purchased by Kinney National Co., which was later reincorporated as Warner Communications in 1972, when it spun off its non-entertainment assets due to a financial scandal over its parking operations. In 1989, Warner Bros. became a subsidiary of Time Warner, a merger between Warner Communications and Time, Inc. In 1992, Time Warner formed Time Warner Entertainment by merging all of its entertainment operations for the first time. In 2001, internet giant AOL merged with Time Warner to become AOL Time Warner, but its name was reverted back to Time Warner two years later due to lawsuits and losing $99 billion from the collapse of the dot-com bubble. AOL officially split from Time Warner in 2009. In 2018, after numerous legal hurdles, telecommunications company AT&T acquired Time Warner, which was later renamed WarnerMedia in 2018. The status of the acquisition was settled in February 2019, when it was upheld on appeal and the Justice Department declined to pursue their case against the acquisition any further.

In May 2021, AT&T announced that it would spin-off its media properties to Discovery, Inc., creating the combined company Warner Bros. Discovery. Today, with the exceptions of some films WB merely distributed, such as Sayonara (currently owned by the estate of Samuel Goldwyn), Moby Dick (currently owned by MGM), Rope (currently owned by Universal), and Hondo (owned by Batjac Productions with distribution exclusively handled by Paramount), the pre-1950 catalog is held by Warner subsidiary Turner Entertainment Co.