Aaron Harlan ( born September 8, 1802 Warren County, Ohio; † January 8, 1868 in San Francisco, California ) was an American politician. Between 1853 and 1859 he represented the state of Ohio in the U.S. House of Representatives.
Aaron Harlan was a cousin of Kongressabegeordneten Andrew J. Harlan (1815-1907) from Indiana. He attended the common schools. After a subsequent study of law and qualifying as a lawyer, he began in 1825 to work in Xenia in this profession. At the same time he embarked on a political career. From 1832 to 1833 he sat as an MP in the House of Representatives from Ohio; in the years 1838, 1839 and 1849 he was a member of the State Senate. In 1841 he moved to a farm near Yellow Springs, where he continues to practice as a lawyer. In the presidential election of 1844 he was an elector for Henry Clay. Harlan was a member of the Whig party. In 1850 he took part in a constitutional convention of his state as a delegate.
In the congressional elections of 1852 Harlan was in the seventh election district of Ohio in the U.S. House of Representatives in Washington DC chosen, where he became the successor of Nelson Barrere on March 4, 1853. After two re- election he was able to complete in Congress until March 3, 1859 three legislative periods. These were shaped by the events leading up to the Civil War. During his three terms of office he represented three different parties. At the beginning he still belonged to the Whigs. Thereafter he joined the short-lived opposition party, for which he was a candidate in 1854. During his last term in Congress, he was a member of the Republican Party. In 1858 he was not re-elected.
After the end of his time in the U.S. House of Representatives Aaron Harlan again worked as a lawyer and also in agriculture. In 1861 he applied unsuccessfully to return to Congress. In 1862 he was lieutenant colonel in the state militia during the Civil War. In 1864 he moved to San Francisco, where he died on January 8, 1868.