The Nauvoo Expositor was a newspaper in Nauvoo, Illinois, that published only one issue, on June 7, 1844. Its publication, the destruction of the printed copies (which, according to the Nauvoo Charter, was the legal consequence of a newspaper deemed a public nuisance by the city council, including Joseph Smith), and the destruction of the printing press by the mob who followed the sheriff sent to collect the printed papers, set off a chain of events that led to Smith's death.

The Expositor was founded by several seceders from the Church of Jesus Christ of Latter Day Saints and some non-Mormons in the Nauvoo area. The single edition of the newspaper was critical of Smith and other church leaders. Specifically, Smith was criticized for teaching doctrines such as plural marriage and exaltation (the ability to become gods by creating and peopling new worlds).

In response to the newspaper's publication, Smith and the Nauvoo City Council declared the paper a public nuisance, and ordered the copies of the printed edition of the paper to be destroyed. The town marshal carried out the order during the evening of June 10. As the sheriff set out to collect and destroy the printed pages, a mob began to follow him. Angry at the inflammatory articles in the paper, the mob, without consent of the city council, proceeded into the printing office and destroyed the press itself.

The destruction of the press led to charges of riot against Smith and other members of the council. After Smith surrendered on the charges, he was also charged with treason against Illinois. Smith was killed by a mob while awaiting a trial in Carthage Jail.