Indiana Territory: Governors: 1800-1816
| Secretary of the Territory (ex officio) | |
| 22? Jul 1800 - 10 Jan 1801 | John Gibson [1] |
| Governor and Commander-in-Chief of the Indiana Territory [2] | |
| 10 Jan 1801 - Jul/Aug 1812 | William Henry Harrison [3][4] |
| Acting Governor of the Indiana Territory | |
| Jul/Aug 1812 - May 1813 | John Gibson |
| Governor and Commander-in-Chief of the Indiana Territory | |
| 7? May 1813 - 7 Nov 1816 | Thomas Posey [5][6] |
- The government of the Indiana Territory was established in July 1800, as evidenced by the journal of executive proceedings, which begins with an entry dated 22 Jul 1800 relating to the appointment of territorial officials by Gibson, who arrived at Vincennes on that date or shortly before.
- Also in official use: Governor and Commander-in-Chief of the Indiana Territory, and of the District of Louisiana (during the period when he exercised the functions of governor of the District of Louisiana, 1 Oct 1804 - 3 Jul 1805).
- Also in Missouri and the United States.
- Harrison was commissioned as governor on 13 May 1800 and took the oath of office upon his arrival at Vincennes on 10 Jan 1801. Shortly before his appointment as commander-in-chief of the Army of the Northwest, he left Indiana in late July or early August 1812, whereupon the functions of governor devolved on Secretary Gibson. Acting on Harrison's letter of resignation written at Delaware, Ohio, on 28 Dec 1812, the President of the United States commissioned Thomas Posey as governor on 3 Mar 1813.
- A memorial to Congress written by Gibson on 10 Jun 1813 states that Posey took office in May 1813. In a letter to the Secretary of War, Posey reported that he had arrived at Jeffersonville, Indiana, "on the 7th ult." Although the date attached to the letter is clearly erroneous, the postmark reads "Vincennes, May 12th."
- Following the adoption of the Constitution of the State of Indiana, the governor, secretary, judges, and other officers of the territorial government were authorized by a provision of the Constitution to continue in office until superseded.