Sue Lyon was chosen for the title role partly due to the size of her breasts. Stanley Kubrick had been warned that the censors felt strongly about the use of a less developed actress to portray the sexually active 14-year-old.
Vladimir Nabokov's original screenplay diverged greatly from the novel, but only a portion of it was used by Stanley Kubrick, even though Nabokov gets screen credit. Nabokov later published it as "Lolita: A Screenplay". The unused screenplay featured an Alfred Hitchcock-like cameo for Nabokov, who is referred to as "that nut with a butterfly net" (Nabokov was well known as an amateur lepidopterist). Although he generally admired the movie adaptation of his book, Nabokov regretted the waste of his time in writing a screenplay which was altered so drastically during filming.
James Mason was the first choice of director Stanley Kubrick and producer James B. Harris for the role of Humbert Humbert, but he initially declined due to a Broadway engagement. Laurence Olivier then refused the part, apparently on the advice of his agents. Kubrick considered Peter Ustinov, but decided against him. Harris then suggested David Niven; Niven accepted the part, but then withdrew for fear the sponsors of his TV show, Four Star Playhouse (1952), would object. Mason then withdrew from his play and got the part. Harris denies claims that Noel Coward also rejected the role.
Since the censors would allow nothing close to a suggestion of pedophilia, Lolita's age had to be increased from 12 in Vladimir Nabokov's original novel to 14 for the film. They also objected to a scene where Humbert Humbert was to gaze at Lolita's picture while in bed with her mother Charlotte; in the end, the scene was filmed with Charlotte lying fully dressed on the bed and Humbert lying beside her wearing a robe.
According to Elstree Studios records, Lolita was filmed from Nov 1960 to Feb 1961. The studio charged £34,000 for the sound stage rentals. Sadly, the sound stages used for the film were demolished to make way for a Tesco store.
Although story takes place all across the United States, many of major sets and exteriors (hotel, hospitals, even residential streets), clearly look more like locales in England, where picture was actually shot.
The distinctive Flemish-Gothic spires of the Delaware & Hudson Building in Albany, New York can be seen in the background, as Humbert drives to Lolita's house near the end of the movie. This would indicate that she was living in or near the town Rensselaer.