From the formation of the provinces in 1791 down to the year 1841, the Lieutenant Governors and Administrators in Upper Canada (Ontario) and Lower Canada (Quebec) were appointed by the Crown in England and held ultimate power in the province. They were advised by the appointed Executive Council. The counties returned elected legislatures which held little actual power separate from the executive authority.
In Upper Canada, the Administrators (Admin) were permanent residents of the province and served during the absence of a Lieutenant Governor (Lt Gov).
Lt Gov 12 Sep 1791 - 10 Apr 1799 Col. John Graves Simcoe
Admin 20 Jul 1796 - 17 Aug 1799 Peter Russell
Lt Gov 10 Apr 1799 - 21 Aug 1805 Lt. Gen. Peter Hunter
Admin 11 Sep 1805 - 25 Aug 1806 Alexander Grant
Lt Gov 25 Aug 1806 - 09 Oct 1811 Francis Gore
Admin 09 Oct 1811 - 13 Oct 1812 Maj. Gen. Isaac Brock
Admin 20 Oct 1812 - 19 Jun 1813 Maj. Gen. Roger Hale Sheaffe
Admin 19 Jun 1813 - 13 Dec 1813 Maj. Gen. Francis, Baron de Rottenbury
Admin 13 Dec 1813 - 15 Apr 1815 Lt. Gen. Sir Gordon Drummond
Lt Gov 25 Apr 1815 - 01 Jul 1815 Lt. Gen. Sir George Murrow
Lt Gov 01 Jul 1815 - 21 Sep 1815 Maj. Gen. Sir Francis F. P. Robinson
Lt Gov 21 Sep 1815 - 06 Jan 1818 Francis Gore
Admin 11 Jun 1817 - 13 Aug 1818 Lt. Col. Samuel Smith
Lt Gov 13 Aug 1818 - 23 Aug 1828 Maj. Gen. Sir Peregrine Maitland
Lt Gov 04 Nov 1828 - 30 Nov 1835 Maj. Gen. Sir John Colborne
Lt Gov 25 Jan 1836 - 23 Mar 1838 Sir Francis Bond Head
Lt Gov 23 Mar 1838 - 09 Feb 1841 Maj. Gen. Sir George Arthur
Admin 25 Aug 1791 - 24 Sep 1793 Alured Clarke
Lt Gov 12 Sep 1791 - 21 Jan 1796 Alured Clarke
Lt Gov 21 Jun 1796 - 15 Dec 1796 Gen. Robert Prescott
Admin 12 Jul 1796 - 27 Apr 1797 Gen. Robert Prescott
Lt Gov 04 Nov 1797 - 29 Nov 1808 R. S. Milnes
Admin 12 Aug 1804 - 24 Oct 1807 Thomas Dunn
Lt Gov 29 Nov 1808 - 27 Jan 1812 Francis N. Burton
Admin 19 Jun 1811 - 14 Sep 1811 Thomas Dunn
Admin 09 Apr 1812 - Maj. Gen. Isaac Brock
Admin 20 Feb 1813 - 30 Nov 1814 Baron F. De Rothenbury
Admin 04 Apr 1815 - 21 May 1816 Lt. Gen. Sir Gordon Drummond
Admin 21 May 1816 - 15 Jul 1816 Maj. Gen. John Wilson
Admin 20 Sep 1819 - 17 Mar 1820 James Monk
Admin Lord Dalhousie
Admin 17 Mar 1820 - 19 Jun 1820 Sir Peregrine Maitland
Admin 07 Jun 1824 - 16 Sep 1828 Sir Francis N Burton
Admin 08 Sep 1828 - 20 Oct 1830 Sir James Kempt
Admin 20 Oct 1830 - 04 Feb 1831 Lord Aylmer
Admin 27 Feb 1838 - 17 Jan 1839 Sir John Colborne
Admin 18 Nov 1839 - 31 Jul 1840 Sir Richard D. Jackson