William Lattimore (February 9, 1774 – April 3, 1843) was Delegate to the United States House of Representatives from Mississippi Territory. Lattimore was born in Norfolk, Virginia on February 9, 1774. William attended the common schools, where he studied medicine. He later moved to Natchez, Mississippi Territory, and practiced his profession. When the Mississippi Territory was formed in 1798 he took an active part in the organization of the government. Lattimore was elected as a Delegate to the 8th and 9th Congresses that lasted (March 4, 1803 – March 3, 1807), he was also elected to the 13th and 14th Congresses (March 4, 1813 – March 3, 1817) as well. William was a delegate to the first State constitutional convention of Mississippi in 1817, appointed a censor of the medical profession under the constitution and code, and one of the commissioners to select the site for the seat of the new State government. Lattimore died in Natchez, Mississippi on April 3, 1843.