Arrowsmith is a novel by American author Sinclair Lewis, first published in 1925. It won the 1926 Pulitzer Prize. Lewis was greatly assisted in its preparation by science writer Paul de Kruif, who received 25% of the royalties on sales, although Lewis was listed as the sole author.

Harry Sinclair Lewis was an American novelist, short-story writer, and playwright. In 1930, he became the first author from the United States to receive the Nobel Prize in Literature, which was awarded "for his vigorous and graphic art of description and his ability to create, with wit and humor, new types of characters." Lewis wrote six popular novels: Main Street (1920), Babbitt (1922), Arrowsmith (1925), Elmer Gantry (1927), Dodsworth (1929), and It Can't Happen Here (1935).