The Academy of Motion Picture Arts and Sciences (AMPAS) presents the grand annual Academy Awards to honor excellence and achievements in the American and international film industry. Eligible nominees in different categories are determined following certain nomination rules and eligibility criteria laid down by governing body of the organization. Voting membership of AMPAS votes to select final nominees from the eligible nominees through a systematic online voting procedure. The auditing firm PricewaterhouseCoopers processes and tabulates these votes to determine final nominees, names of whom are then announced.

Strict nomination rules, directives and eligibility criteria are maintained by the AMPAS for Oscar nominations. Rules 2 and 3 of the AMPAS' rules for eligibility necessitate a film to play its Oscar-qualifying run in Los Angeles County, California, that is it must be screened at a commercial theatre in Los Angeles county between January 1 and December 31 of the preceding calendar year for a minimum of seven days in a row and for at least thrice on each day with at least one such daily screening occurring between 6 pm and 10 pm local time, to qualify itself for nomination for an award in a given year. This criterion is however not required for nominating films for the Best International Feature Film award and certain other categories for which different eligibility requirements are followed.

Rule 2 also require a film to be of feature-length, considering its duration to be at least 40 minutes, barring for short-subject awards. The rule also specifies that the film must be formatted with a width of the standard 35 mm format or 70 mm format otherwise in 24 frame/s or 48 frame/s progressive scan digital cinema format having a projector resolution of at least 2048 by 1080 pixels. Another eligibility rule requires producers of the films to submit an Official Screen Credits online form within a stipulated date. Production credits for all associated categories are mentioned in the forms which after checking are kept in a Reminder List of Eligible Releases.

A film to become eligible for an Oscar nomination in the Best International Feature Film award category does not require an US screening but has to be submitted as the official selection by its country of origin and must include English subtitles. A country can submit only one film a year for this category.

To become eligible for a Best Documentary Feature nomination, a film must be commercially screened for a week in Los Angeles County and in New York City in the preceding year; or garner a qualifying award from a Documentary Feature Qualifying Festival listed competitive film festival, with or without any public screening or distribution; or being officially selected and submitted in the International Feature Film category by its country of origin. With regard to theatrical screenings of the documentaries, number and times of screenings follow the same eligible criteria as for non-documentary films. Moreover AMPAS also requires a documentary to have been reviewed by a critic from Time Out New York, The New York Times, LA Weekly or the Los Angeles Times. The 2016 American documentary O.J.: Made in America (duration 467 minutes) that was released as a five-part miniseries as well as in theatrical format won Best Documentary Feature award at the 89th Academy Awards. It marked as the longest film that bagged an Oscar nomination and win, and also as the last of its kind that garnered an Oscar nomination and win, as since the next Oscar ceremony a new rule was introduced that made any multi-part or limited series ineligible for nomination in this category.

The calendar year of October 1 to September 30 is considered for awards for short film categories. A short film to become eligible for Oscar nomination must be screened in theatre in either New York City or Los Angeles County for at least a week; or win specified awards at an AMPAS designated competitive film festival, regardless of prior public distribution; or have won a gold, silver, or bronze medal in a specified category during the previous Student Academy Awards. A short film needs only one screening a day to qualify. To become eligible for the Best Documentary Short Subject nomination, a short film must be screened anytime from 12 pm to 10 pm local time; while no clearly defined start time is necessary for screening of short films for getting nominated in the Best Live Action Short Film and Best Animated Short Film categories.

Online voting process for selecting nominees starts in December with PricewaterhouseCoopers sending ballots along with copies of Reminder List of Eligible Releases to voting members through mail. Members of a particular branch select nominees from their branch only, which means only actors can vote for nominating actors, directors can vote for nominating directors, and so on. This is followed for most of the categories while for the Best Picture category nominees are selected by all voting members. A form of the single transferable vote (STV) system is used to select nominees within each major category. Under this process, a member casts vote in the form of a ranked-choice ballot that is rank preferentially up to five nominees (ten in case of Best Picture category). From 2013 AMPAS uses re-weighted score voting system for choosing nominees for Best Visual Effects. Nominees for some categories like International Feature Film and Animated Feature are chosen by special screening committees composed of members from all sections. As per rules, the voters must return their secret ballots directly to PricewaterhouseCoopers within two weeks for tabulation of the votes. Nomination results were made public by AMPAS in early February till 2003 following which it announced the results in mid-January till 2020, in March in 2021 and again in early February in 2022.