John Tyler
| Rank: | 10th (1841-1845) |
| Followed: | William Henry Harrison |
| Succeeded by: | John Knox Polk |
| Date of Birth | March 29, 1790 |
| Place of Birth: | Greenway, Virginia |
| Date of Death: | January 18, 1862 |
| Place of Death: | Richmond, Virginia |
| First Lady: | Letitia Christian, Julia Gardiner |
| Occupation: | lawyer |
| Political Party: | Whig |
| Vice President: | none |
John Tyler was the 10th (1841-1845) President of the United States of America.
Tyler was elected Vice President in 1840 as running mate to William Henry Harrison, and assumed the presidency upon Harrison's death. Tyler was the first such vice-president to assume the presidency in this manner. His presidency was never taken seriously in his time; he was usually referred to as the "Acting President". Further, Harrison was to have been a genial figurehead controlled by Whig Party leaders, particularly Henry Clay. Tyler attempted to establish his own policy, and this put him at odds with Clay and others.
Tyler's last act in office was perhaps the most significant: he signed the bill annexing Texas, which had formerly been part of Mexico. This act triggered war with Mexico.