Killers of the Flower Moon is a 2023 American epic revisionist Western[4] crime drama film[5] directed and produced by Martin Scorsese, who co-wrote the screenplay with Eric Roth, based on the 2017 book of the same name by David Grann. Its plot centers on a series of Oklahoma murders in the Osage Nation during the 1920s, committed after oil was discovered on tribal land. Leonardo DiCaprio, Robert De Niro, and Lily Gladstone lead an ensemble cast that includes Jesse Plemons, Tantoo Cardinal, John Lithgow, and Brendan Fraser. It is the sixth feature film collaboration between Scorsese and DiCaprio and the tenth between Scorsese and De Niro. It is the eleventh collaboration between Scorsese and his musical partner, Robbie Robertson, who passed away two months before the film's release; the film is dedicated to Robertson.

Development began in March 2016 when Imperative Entertainment won the film adaptation rights to the book. Scorsese and DiCaprio were attached to the film in 2017, with production initially expected to begin in early 2018. Following several pushbacks and delays in response to the COVID-19 pandemic, production was scheduled to commence in February 2021 with Apple TV+ confirmed to finance and distribute the film alongside Paramount Pictures. Principal photography ultimately took place in Osage County and Washington County between the spring and fall of 2021. The film is produced by Scorsese's Sikelia Productions and DiCaprio's Appian Way Productions with its $200 million budget reportedly the largest amount ever spent on a film shot in Oklahoma.

Killers of the Flower Moon premiered at the 76th Cannes Film Festival on May 20, 2023, and was released in the United States on October 20, 2023 by Apple TV+, under their Apple Original Films label, and by Paramount Pictures, and was screened in IMAX. and is set for an unspecified streaming release on Apple TV+. The film received praise from critics for its direction, performances, and production values, though the 206-minute runtime drew some criticism.