The Scopes trial, formally The State of Tennessee v. John Thomas Scopes, and commonly referred to as the Scopes Monkey Trial, was an American legal case from July 10 to July 21, 1925, in which a high school teacher, John T. Scopes, was accused of violating Tennessee's Butler Act, which had made it illegal for teachers to teach human evolution in any state-funded school. The trial was deliberately staged in order to attract publicity to the small town of Dayton, Tennessee, where it was held. Scopes was unsure whether he had ever actually taught evolution, but he incriminated himself deliberately so the case could have a defendant.

Scopes was found guilty and was fined $100 (equivalent to $1,500 in 2021), but the verdict was overturned on a technicality. The trial served its purpose of drawing intense national publicity, as national reporters flocked to Dayton to cover the high-profile lawyers who had agreed to represent each side. William Jennings Bryan, three-time presidential candidate and former secretary of state, argued for the prosecution, while Clarence Darrow served as the defense attorney for Scopes. The trial publicized the fundamentalist–modernist controversy, which set Modernists, who said evolution could be consistent with religion, against fundamentalists, who said the word of God as revealed in the Bible took priority over all human knowledge. The case was thus seen both as a theological contest and as a trial on whether evolution should be taught in schools.