There Will Be Blood is a 2007 American epic period drama film written and directed by Paul Thomas Anderson, loosely based on the 1927 novel Oil! by Upton Sinclair. It stars Daniel Day-Lewis as Daniel Plainview, a silver miner turned oilman on a ruthless quest for wealth during Southern California's oil boom of the late 19th and early 20th centuries. Paul Dano, Kevin J. O'Connor, Ciarán Hinds, and Dillon Freasier co-star. The film was produced by Ghoulardi Film Company and distributed by Paramount Vantage and Miramax Films.

The first public screening of There Will Be Blood was on September 29, 2007, at Fantastic Fest in Austin, Texas. The film was released on December 26, 2007, in New York City and Los Angeles where it grossed US$190,739 on its opening weekend. The film then opened in 885 theaters in selected markets on January 25, 2008, grossing $4.8 million on its opening weekend. The film went on to make $40.2 million in North America and $35.9 million in the rest of the world, with a worldwide total of $76.1 million, well above its $25 million budget; however, the prints and advertising cost for the film's United States release cost about $40 million.

There Will Be Blood received acclaim for its cinematography, Anderson's direction and screenplay, score, and the performances of Day-Lewis and Dano. Day-Lewis won the Academy Award, BAFTA, Golden Globe, Screen Actors Guild, NYFCC and IFTA Best Leading Actor awards for the role. It has been widely regarded by critics as one of the greatest films of the 21st century, and it appeared on many critics' "top ten" lists for 2007, including the American Film Institute, the National Society of Film Critics, the National Board of Review, and the Los Angeles Film Critics Association. At the 80th Academy Awards, the film was nominated for eight Oscars (tying with another Miramax/Paramount Vantage co-production No Country for Old Men). The nominations included Best Picture, Best Director and Best Adapted Screenplay for Anderson. Along with Day-Lewis' Oscar for Best Actor, Robert Elswit won the award for Best Cinematography.