
The first Academy Awards ceremony was held in 1929, and Charlie Chaplin's film 'The Circus' was nominated in four categories: Best actor, best writer, best director for a comedy, and outstanding picture.
In fear that Chaplin might take all four golden trophies home, the Academy decided to revoke one of his nominations. However, they decided to honour him with a special honorary award for acting, writing, directing, and producing the film.

Considered one of the greatest films of all time, Francis Ford Coppola's 1972 crime drama 'The Godfather' in 1972 historically bagged nine Academy Awards, including Best Picture, Best Director, and Best Actor for Marlon Brando, among others. The film's composer, Nino Rota, also nabbed a nomination in the Best Original Score category, but his nomination was revoked after the Academy learned that he used some of his own scores from the Italian comedy 'Fortunella'.
However, two years later, he won an Oscar for 'The Godfather II' in the Best Original Score category.

John Krasinski's '13 Hours' is the latest film in the Academy history whose nomination was revoked. In 2016, the movie bagged a nom in the Best Achievement in Sound Mixing category for the members of the sound team (Gary Summers, Jeffrey J. Haboush, Mac Ruth, and Greg P. Russell).
However, the nomination of Greg P. Russell was taken away after over “telephone lobbying” just a day before the Academy nomination.
In the statement released, Academy said: “Upon recommendation by the Sound Branch Executive Committee, the Academy’s Board of Governors voted Thursday (2/23) to rescind the Sound Mixing nomination for Greg P. Russell from 13 Hours: The Secret Soldiers of Benghazi for violation of Academy campaign regulations. The decision was prompted by the discovery that Russell had called his fellow members of the Sound Branch during the nominations phase to make them aware of his work on the film, in direct violation of a campaign regulation that prohibits telephone lobbying. An additional nominee for 13 Hours: The Secret Soldiers of Benghazi will not be named in his place. The remaining Sound Mixing nominees for the film are Gary Summers, Jeffrey J. Haboush and Mac Ruth.''

In 1954, the John Wayne directorial 'Hondo' was nominated in the 'Best Story' category; however, the film was disqualified when the Academy found out that the film is not an original work and its script is based on a short story called 'The Gift of Cochise.'

The 'Alone Yet Not Alone' nomination cancellation is one of the most talked-about controversies in Oscar history. The film was nominated for Best Original Song in 2014, only to get disqualified two years later.
This was the first time in the history of the Oscars that any nomination was disqualified after the ceremony. The shocking step was taken after the Academy board came to know that the song's nominated writer, Bruce Broughton, "emailed [some of the other 239] members of the branch to make them aware of his submission during the nominations voting period," the Academy said in a statement released back then.

In this one, it was actually the Academy's mistake. In 1957, the organisation mistakenly nominated writers Edward Bernds and Elwood Ullman for Best Story for the musical comedy 'High Society', a film that they never wrote.
Bernds and Ullman have written the film of the same name, and that is what confused the board members.

In 2012, a 25-minute Norwegian short film, 'A Tuba Atlantic,' was nominated for Best Live-Action Short Film, but the nomination was later disqualified after it was discovered that the film had broken one of the Academy rules.
Actually, the film was aired on Norwegian television before its theatrical release.

'Young Americans', directed by Alexander Grasshoff, won the Academy Award for Best Documentary in 1969. Unfortunately, the Oscar was taken back a month later after the Academy found out that the film had been released in theatres in 1967, making it ineligible for the 1968 ceremony.
'Young Americans' is the only documentary in Academy history whose Oscar has been taken away after the ceremony.