Tyler embarked on his long public career in December 1811 when he began the first of five consecutive one-year terms representing Charles City County in the House of Delegates. Despite his youth, on December 8, 1815, the General Assembly elected him to the Council of State. In November 1816 Tyler won a special election to a vacant seat in the House of Representatives from the district that included the city of Richmond and Charles City, Hanover , Henrico , and New Kent counties. He won election to full terms in 1817 and 1819. A Democrat-Republican supporting states' rights, limited government, and a strict interpretation of the Constitution, Tyler opposed rechartering the Bank of the United States, increasing protective tariffs, appropriating federal funds for internal improvements, and Andrew Jackson's military campaigns during the First Seminole War.

Tyler initially opposed the Missouri Compromise of 1820, because he viewed it as unconstitutional and thought that new states should decide for themselves whether to permit slavery . A lifelong slaveholder, he believed the institution was a necessary evil and that it needed to expand into the western territories to disperse the slave population, which would ease problems of slave management and allow for better treatment of bondspeople because of increased demand for their labor. Tyler also argued that the political viability for eventual emancipation could be strengthened if the slave population of the older southern states was thinned out. He eventually voted for the compromise but later regretted his decision because he believed that it contributed to sectional discord in subsequent decades.

Poor health prohibited him from seeking another term in 1821, but two years later Charles City County voters returned him to the House of Delegates, where he served three consecutive one-year terms. The General Assembly elected him to a one-year term as governor on December 10, 1825. Tyler busied himself with the routine duties of the chief executive, which often related to state appointments, public improvements, the penitentiary, the militia, and military bounty claims. The assembly reelected him to another term in December 1826, but on January 13, 1827, it elected him to the U.S. Senate. Tyler's resignation as governor took effect on March 4, the day the congressional term began. Elected as a Jacksonian, Tyler objected to funding internal improvements, raising tariffs, and rechartering the Bank of the United States.