John Bell (February 18, 1796 – September 10, 1869) is an American politician, attorney, and plantation owner.

One of Tennessee's most prominent antebellum politicians, he serves in the House of Representatives from 1827 to 1841, and in the Senate from 1847 to 1859.

He is Speaker of the House for the 23rd Congress (1834–1835), and briefly serves as Secretary of War during the administration of William Henry Harrison (1841).

In 1860, he runs for president as the candidate for the Constitutional Union Party, a third party which takes a neutral stance on the issue of slavery.

Initially an ally of Andrew Jackson, Bell turns against Jackson in the mid-1830s and aligns himself with the Whig Party, a shift which earns him the nickname, "The Great Apostate."

He consistently battles Jackson's allies, namely James K. Polk, over issues such as the national bank and the election spoils system.

Following the death of Hugh Lawson White in 1840, Bell becomes the acknowledged leader of Tennessee's Whigs.

Although a slaveowner, Bell is one of the few southern politicians to oppose the expansion of slavery in the 1850s, and campaigns vigorously against secession in the years leading up to the American Civil War.

During his 1860 presidential campaign, he argues that secession is unnecessary since the Constitution protected slavery, an argument which resonates with voters in border states, helping him capture the electoral votes of Tennessee, Kentucky and Virginia.

After the Battle of Fort Sumter in April 1861, Bell abandons the Union cause and supports the Confederacy.