"The War of the Worlds" was a Halloween episode of the radio series The Mercury Theatre on the Air directed and narrated by Orson Welles as an adaptation of H. G. Wells's novel The War of the Worlds (1898). It was performed and broadcast live at 8 pm ET on October 30, 1938 over the Columbia Broadcasting System radio network. The episode is famous for inciting a panic by convincing some members of the listening audience that a Martian invasion was taking place, though the scale of panic is disputed, as the program had relatively few listeners.The episode begins with an introductory monologue based closely on the opening of the original novel, after which the program takes on the format of an evening of typical radio programming being periodically interrupted by news bulletins. The first few bulletins interrupt a program of live music and are relatively calm reports of unusual explosions on Mars followed by a seemingly unrelated report of an unknown object falling on a farm in Grover's Mill, New Jersey. The crisis escalates dramatically when a correspondent reporting live from Grover's Mill describes creatures emerging from what is evidently an alien spacecraft. When local officials approach the aliens waving a flag of truce, the "monsters" respond by incinerating them and others nearby with a heat ray which the on-scene reporter describes in a panic until the audio feed abruptly goes dead. This is followed by a rapid series of news updates detailing the beginning of a devastating alien invasion and the military's futile efforts to stop it. The first portion of the episode climaxes with another live report from the rooftop of a Manhattan radio station. The correspondent describes crowds fleeing clouds of poison smoke released by giant Martian "war machines" and "dropping like flies" as the gas approaches his location. Eventually he coughs and falls silent, and a lone ham radio operator asks, "Is there anyone on the air? Isn't there... anyone?" with no response. The program takes its first break thirty minutes after Welles's introduction.

The second portion of the show shifts to a conventional radio drama format that follows a survivor (played by Welles) dealing with the aftermath of the invasion and the ongoing Martian occupation of Earth. The final segment lasts for about sixteen minutes, and like the original novel, concludes with the revelation that the Martians have been defeated by microbes rather than by humans. The broadcast ends with a brief "out of character" announcement by Welles in which he compares the show to "dressing up in a sheet and jumping out of a bush and saying 'boo!'"

Welles's "War of the Worlds" broadcast has become famous for convincing some of its listeners that a Martian invasion was actually taking place due to the "breaking news" style of storytelling employed in the first half of the show. The illusion of realism was supported by the Mercury Theatre on the Air's lack of commercial interruptions, which meant that the first break in the drama came after all of the alarming "news" reports had taken place. Popular legend holds that some of the radio audience may have been listening to The Chase and Sanborn Hour with Edgar Bergen and tuned in to "The War of the Worlds" during a musical interlude, thereby missing the clear introduction indicating that the show was a work of science fiction. Contemporary research suggests that this happened only in rare instances.:6769In the days after the adaptation, widespread outrage was expressed in the media. The program's news-bulletin format was described as deceptive by some newspapers and public figures, leading to an outcry against the broadcasters and calls for regulation by the FCC. Welles apologized at a hastily-called news conference the next morning, and no punitive action was taken. The broadcast and subsequent publicity brought the 23-year-old Welles to the attention of the general public and gave him the reputation of an innovative storyteller and "trickster".

George Orson Welles (May 6, 1915 – October 10, 1985) was an American director, actor, screenwriter, and producer who is remembered for his innovative work in radio, theatre and film. He is considered to be among the greatest and most influential filmmakers of all time.While in his 20s, Welles directed high-profile stage productions for the Federal Theatre Project, including an adaptation of Macbeth with an entirely African American cast and the political musical The Cradle Will Rock. In 1937, he and John Houseman founded the Mercury Theatre, an independent repertory theatre company that presented a series of productions on Broadway through 1941, including Caesar (1937), an adaptation of William Shakespeare's Julius Caesar.

In 1938, his radio anthology series The Mercury Theatre on the Air gave Welles the platform to find international fame as the director and narrator of a radio adaptation of H. G. Wells's novel The War of the Worlds, which caused some listeners to believe that an invasion by extraterrestrial beings was in fact occurring. Although reports of panic were mostly false and overstated, they rocketed 23-year-old Welles to notoriety.

His first film was Citizen Kane (1941), which is consistently ranked as one of the greatest films ever made and which he co-wrote, produced, directed and starred in as the title character, Charles Foster Kane. Welles released twelve other features, the most acclaimed of which include The Magnificent Ambersons (1942), The Lady from Shanghai (1947), Touch of Evil (1958), The Trial (1962), Chimes at Midnight (1965) and F for Fake (1973). His distinctive directorial style featured layered and nonlinear narrative forms, uses of lighting such as chiaroscuro, unusual camera angles, sound techniques borrowed from radio, deep focus shots and long takes. He has been praised as "the ultimate auteur".: 6 Welles was an outsider to the studio system and struggled for creative control on his projects early on with the major film studios in Hollywood and later in life with a variety of independent financiers across Europe, where he spent most of his career. Many of his films were either heavily edited or remained unreleased. Some, like Touch of Evil, have been painstakingly re-edited from his notes. With a development spanning almost 50 years, Welles's final film, The Other Side of the Wind, was posthumously released in 2018.

Welles had three marriages, including one with Rita Hayworth, and three children. Known for his baritone voice, Welles performed extensively across theatre, radio, and film. He was a lifelong magician, noted for presenting troop variety shows in the war years. In 2002, he was voted the greatest film director of all time in two British Film Institute polls among directors and critics. In 2018, he was included in the list of the 50 greatest Hollywood actors of all time by The Daily Telegraph.