On January 18, 1960, Frank Morris (Clint Eastwood) arrives at the maximum security prison Alcatraz. Soon after arriving, he is sent in to meet the warden (Patrick McGoohan), who curtly informs him that no inmate has ever successfully escaped from Alcatraz. Among the inmates, Morris makes acquaintances with the eccentric Litmus, (Frank Ronzio) who is fond of desserts, English (Paul Benjamin), a black inmate serving two life sentences for killing two white men in self-defense and the elderly artist and chrysanthemum grower Doc (Roberts Blossom).
Morris also makes an enemy of a rapist called Wolf (Bruce M. Fischer), who harasses him in the showers and later attacks him in the prison yard with a knife; both men spend time in the hole. When the warden discovers that Doc has painted an ungainly caricature of him, as well as other policemen on the island itself, he permanently removes Doc's painting privileges; in response, a depressed Doc hacks off his own fingers with a hatchet from the prison workshop and is led away. Later, Morris encounters bank robber brothers John and Clarence Anglin (Fred Ward and Jack Thibeau), who are his old friends from another prison sentence, and he makes the acquaintance of prisoner Charley Butts (Larry Hankin). Later, during mealtime, Morris places one of Doc's chrysanthemums at the table in honor of Doc, but the warden stops by and crushes it. Litmus is enraged, but as he reaches out to grab the warden, he suffers a fatal heart attack. The warden coldly reminds Morris that "some men are destined never to leave Alcatraz—alive."
Morris notices that the concrete around the grille in his cell is weak and can be chipped away, which evolves into an escape plan. Over the next few months Morris, the Anglins and Butts dig through the walls of their cells with spoons (which have been soldered into makeshift shovels), make papier-mâché dummies to act as decoys, and construct a raft out of raincoats. On June 11, 1962, the inmates decide to leave. Wolf has been released from solitary confinement and prepares to stab Morris with a knife, but English is able to intercept him. That night, Morris, the Anglins and Butts plan to meet in the passageway and escape. Butts panics and fails to rendezvous with them. Carrying the flotation gear, Morris and the Anglins access the roof and avoid the searchlights. From there, they scramble down the side of the building into the prison yard, climb over a barbed-wire fence and make their way to the shoreline of the island where they inflate the raft. The three men enter the water; partially submerged, they cling to the raft and use their legs as the primary propelling force and kicking. When their escape is discovered the following morning, a massive manhunt ensues. The warden does not want to blemish his perfect record and insists that the men drowned, despite no bodies being found. On a rock on the shore of Angel Island, he finds a chrysanthemum and throws it in the water after being told that they do not grow there.
Alcatraz was closed shortly after the true events on which the film was based. Screenwriter Richard Tuggle spent six months researching and writing a screenplay based on the 1963 non-fiction account by J. Campbell Bruce. He went to the Writers Guild and received a list of literary agents who would accept unsolicited manuscripts. He submitted a copy to each, and also to anybody else in the business that he could cajole into reading it. Everyone rejected it, saying it had poor dialogue and characters, lacked a love interest, and that the public was not interested in prison stories. Tuggle decided to bypass producers and executives and deal directly with filmmakers. He called the agent for director Don Siegel and lied, saying he had met Siegel at a party and the director had expressed interest in reading his script. The agent forwarded the script to Siegel, who read it, liked it, and passed it on to Clint Eastwood.
Eastwood was drawn to the role as ringleader Frank Morris and agreed to star, providing Siegel direct under the Malpaso banner. Siegel insisted that it be a Don Siegel film and outmaneuvered Eastwood by purchasing the rights to the film for $100,000. This created a rift between the two friends. Although Siegel eventually agreed for it to be a Malpaso-Siegel production, Siegel went to Paramount Pictures, a rival studio, and never directed an Eastwood picture again.
Although Alcatraz had its own power plant, it was no longer functional, and 15 miles of cable were required to connect the island to San Francisco's electricity. As Siegel and Tuggle worked on the script, the producers paid $500,000 to restore the decaying prison and recreate the cold atmosphere; some interiors had to be recreated in the studio. Many of the improvements were kept intact after the film was made.
The dangerous escape down the prison wall and into the water was performed without stunt doubles by Eastwood, Fred Ward, and Jack Thibeau, who had both been cast partly for their athleticism. Director Siegel twice thought they had been lost to the treacherous currents.
The film implied that the escape had been successful. While it is not known whether the three escapees survived, supposed sightings of them over the years provide possible evidence that they may have.
The character Charlie Butts is fictional. A fourth inmate, Allen West, did participate in the real escape but was left behind when he couldn't remove his ventilator grille on the night of the escape. He aided the FBI's official investigation of the escape.
The warden is a nameless, fictional character. The film is set between the arrival of Morris at Alcatraz in January 1960 and his escape in June 1962. Shortly after arriving Morris meets the warden, who remains in office over the course of the entire movie. In reality, warden Madigan had been replaced by Blackwell in 1961. The warden character mentions his predecessors Johnston (1934–48) and (incorrectly) Blackwell (1961–63).
Escape from Alcatraz was well received by critics and is considered by many as one of the best films of 1979. Frank Rich of Time described the film as "cool, cinematic grace", while Stanley Kauffmann of The New Republic called it "crystalline cinema". Review aggregation website Rotten Tomatoes retrospectively collected reviews from 22 critics, and gave the film an approval rating of 95%, with an average rating of 6.9/10. The film grossed $5,306,354 in the U.S. during its opening weekend from June 24, 1979, shown on 815 screens. In total, the film earned $43,000,000 in U.S. theaters, making it the 15th highest-grossing picture of 1979.
In 2001, the American Film Institute nominated this film for AFI's 100 Years...100 Thrills.