The NBA playoffs is the annual postseason tournament of the National Basketball Association (NBA) held after the league's regular season to determine the league champion. The playoffs date back to 1947 when the NBA was then known as the Basketball Association of America, and eventually expanded to the present-day four-round, best-of-seven tournament in 2003. Since 2020, it has been held after the preliminary postseason tournament, the NBA play-in tournament. Under the current postseason format since 2021, six teams from each of the two conferences automatically advance to the playoffs based on regular season winning percentage, while those teams finishing seven through 10 from each conference first compete in the play-in tournament to determine the final two playoff seeds. The playoffs culminate with the NBA Finals, where both conference champions from the NBA conference finals play each other.

The top six teams in both the Eastern Conference and Western Conference, ranked by winning percentage, directly advance to the playoffs. Teams ranked seventh through tenth compete in the NBA play-in tournament for the seventh and eighth seeds.

Officially considered separate from the NBA playoffs, the NBA play-in tournament uses a modified Page playoff format in which the seventh- and eighth-place teams play each other in a qualification game, with the winner being given the opportunity to play as the seventh seed of the playoffs. Meanwhile, the ninth- and tenth-place teams play each other in an elimination game, with the loser being eliminated and the winner playing the loser of the seven-eight game in a final game to determine who earns the eighth playoff seed.

Both conferences conduct the playoffs in the traditional bracket format. All rounds are best-of-seven series. Series are played in the 2–2–1–1–1 format, meaning the team with home-court advantage hosts games 1, 2, 5, and 7, while their opponent hosts games 3, 4, and 6, with games 5, 6 and 7 being played if needed. This format has been used since 2014, after NBA team owners unanimously voted to change the format of the NBA Finals from the 2–3–2 format on October 23, 2013. Once the playoffs start, the bracket is fixed; teams are never "reseeded."

If at least two teams within the same conference are tied in overall winning percentage, tiebreaker criteria are used to determine final rankings.

The tiebreaker criteria are as follows, with coin tosses (two teams) or draw of lots (at least three teams) if all of those fail:

Should at least three teams tie, division leaders are given higher seeds regardless of any other criteria. Plus, once any team is eliminated from a tiebreaker, the evaluation goes back to the first step for the remaining teams. Prior to 2016, this rule was also used for two-team ties, but only applied if the two teams have the same head-to-head record.

The National Basketball Association was established in 1949 by merger of the Basketball Association of America (BAA) and National Basketball League but it recognizes the three BAA seasons as part of its own history. In all of its three years the BAA champion was finally determined in a best-of-seven series but its first two tournaments, the 1947 and 1948 BAA playoffs, were otherwise quite different from the third, which 21st-century NBA playoffs nearly match. In 1947 and 1948, the Eastern and Western Division champions were matched in a best-of-seven series following the regular season, whose winner advanced to the championship round. Meanwhile, four runners-up played best-of-three series to determine the other finalist: the two second-place teams were matched in one short series and the two third-place teams in another; the winners of those two series played another one. In 1947, the Philadelphia Warriors won the runners-up bracket and beat the Western champion Chicago Stags four games to one, which the NBA recognizes as its first championship; in 1948 Baltimore won the runners-up and beat Eastern champion Philadelphia in the final. Both tournaments generated one finalist from the Eastern and one from the Western Division, but only by chance.