Pare Lorentz (December 11, 1905 – March 4, 1992) was an American filmmaker known for his movies about the New Deal. Born Leonard MacTaggart Lorentz in Clarksburg, West Virginia, he was educated at West Virginia Wesleyan College and West Virginia University. As a young film critic in New York City and Hollywood, Lorentz spoke out against censorship in the film industry.

As the most influential documentary filmmaker of the Great Depression, Lorentz was the leading US advocate for government-sponsored documentary films. His service as a filmmaker for US Army Air Corps in World War II was formidable, including technical films, documentation of bombing raids, and synthesizing raw footage of Nazi atrocities for an educational film on the Nuremberg Trials. Nonetheless, Lorentz will always be known best as "FDR's filmmaker."

Lorentz left West Virginia after college in 1925, to begin a career as a writer and film critic in New York in 1925. He contributed articles to leading magazines such as Scribner’s, Vanity Fair, McCall's, and Town and Country and co-authored a 1929 book, Censored: the private life of the movie.

His work as a film critic led him to Hollywood, where he wrote several articles on censorship and a pictorial review of the first year of Franklin D. Roosevelt's presidency, The Roosevelt Year: 1933. Roosevelt was impressed with the articles and the book, and in 1936, as President of the United States, invited Lorentz to make a government-sponsored film about the Oklahoma Dust Bowl.

Despite not having any film credits, Lorentz was appointed to the Resettlement Administration as a film consultant. He was given US$6,000 to make a film, which became The Plow That Broke the Plains, a film that showed the natural and man-made devastation caused by the Dust Bowl. Though the tight budget and his inexperience occasionally showed through in the film, Lorentz's script, combined with Thomas Chalmers's narration and Virgil Thomson's score, made the 30-minute movie powerful and moving. The film, which had its first public showing on May 10, 1936 at Washington's Mayflower Hotel, had a preview screening in March at the White House. Roosevelt was impressed and, after his re-election in 1936, gave Lorentz the opportunity to make a film about one of the President's favorite subjects—conservation. Lorentz made The River, a film celebrating the exploits of the Tennessee Valley Authority. The TVA mitigated flooding but, more importantly to Lorentz and to Roosevelt, it put a stop to the prodigious pillaging of the forests by providing cheap, readily available hydro-electric power to a wide area. This film won the "best documentary" category at the Venice International Film Festival. The text of River appeared in book form, and was nominated for the Pulitzer Prize in poetry the same year. It is generally considered his most masterful work.

When Republicans gained seats in Congress in 1938, and the Congressional balance of power shifted in a more conservative direction, the pipeline of Federal commissions for projects like Lorentz's was abruptly halted along with the short-lived existence of the US Film Service, which Lorentz headed. In 1940 he produced Power and the Land promoting the Rural Electric Administration. The REA took over its own production, and the film itself was directed by Joris Ivens, the prolific Dutch filmmaker best known for his anti-fascist documentaries. Lorentz made one more movie before the US involvement in World War II, The Fight for Life (1940), a semi-documentary on the struggle to provide adequate natal (obstetric) care at the Chicago Maternity Center, based on a book by Paul de Kruif. John Steinbeck worked on the project with Lorentz.