Events of 1817

January – March 
 January 19 – An army of 5,423 soldiers, led by General José de San Martín, starts crossing the Andes from Argentina to free Chile and then Peru.
 February 12 – The Argentine/Chilean patriotic army defeats the Spanish in the Battle of Chacabuco.
 March 3
The Alabama Territory is created by splitting the Mississippi Territory in half, 9 months before Mississippi becomes a U.S. state.
President James Madison vetoes John C. Calhoun's Bonus Bill.
 March 4 – James Monroe succeeds James Madison as the President of the United States of America.

April – June 
 April – Earthquake in Palermo, Italy
 April 3 – Princess Caraboo appears in Almondsbury in Gloucestershire, England.
 April 15 – The first American school for the deaf opens in Hartford, Connecticut.
 April 17 – Martin Van Buren passes Erie Canal bill.
 April 28 – Rush-Bagot Treaty is signed.
 May – The General Convention of the Episcopal Church founded General Theological Seminary while meeting in New York City.
 June 5 – First Great Lakes steamer, the Frontenac, is launched.
 June 25 – Large prison riot in Copenhagen prison – army is sent for to quell it.

July – September 
 July 4 – At Rome, New York, construction on the Erie Canal begins.
 August 22 – City of Araraquara, Brazil founded.
 August 23 – Earthquake near the site of the ancient Greek city of Helike results in 65 deaths.

October – December 
 October – President and Mrs. James Monroe move back into the White House, after restoration repairs.
October 31 – Emperor Ninkō accedes to the throne of Japan.
 November 20 – The first Seminole War begins in Florida.
 November 22 – Fredric Cailliaud discovers the old Roman emerald mines at Sikait, Egypt.
 December 10 – Mississippi is admitted as the 20th U.S. state, separated from the Alabama Territory.

Undated 
 Elgin Marbles are displayed in the British Museum.
 John Kidd extracts naphthalene from coal tar.
 Samuel Taylor Coleridge publishes Biographia Literaria.
 A Typhus epidemic occurs in Edinburgh and Glasgow.
 Outbreak of the Pernambucan Revolt.

January – June 
 January 6 – J. J. McCarthy, Irish architect (d. 1882)
 January 8 – Sir Theophilus Shepstone, British-born South African statesman (d. 1893)
 February 19 – King William III of the Netherlands (d. 1890)
 February 22 – Carl Wilhelm Borchardt, German mathematician (d. 1880)
 March 6 – Clémentine of Orléans, daughter of King Louis-Philippe of France and mother of Tsar Ferdinand I of Bulgaria (d. 1907)
 March 22 – Braxton Bragg, American Confederate general (d. 1876)
 May 15 – Debendranath Tagore, Indian philosopher (d. 1905)
 June 30 – Joseph Dalton Hooker, English botanist (d. 1911)

July - December 
 July 12 – Henry David Thoreau, American philosopher (d. 1862)
 July 24 – Adolphe, Grand Duke of Luxembourg (d. 1905)
 August 3 – Archduke Albert, Austrian general (d. 1895)
 August 14 – Alexander H. Bailey, American politician (d. 1874)
 August 24 – Aleksey Konstantinovich Tolstoy, Russian writer (d. 1875)
 October 17 – Sir Syed Ahmed Khan Bahadur Founder of the Two Nation Theory for a future Pakistan (d. 1898)
 November 3 – Leonard Jerome, American entrepreneur and grandfather of Sir Winston Churchill (d. 1891)
 November 12 – Bahá'u'lláh, Persian founder of the Bahá'í Faith (d. 1892)
 November 17 – Benjamin Champney, American painter (d. 1907)
 November 30 – Theodor Mommsen, German writer, Nobel Prize laureate (d. 1903)

Deaths

January – June 
 January 12 – Juan Andres, Spanish Jesuit (b. 1740)
 January 16 – Alexander J. Dallas, American statesman and financier (b. 1759)
 April 4 – André Masséna, French marshal (b. 1758)
 April 12 – Charles Messier, French astronomer (b. 1730)
 June 24 – Thomas McKean, American lawyer and signer of the Declaration of Independence (b. 1734)

July – December 
July 14 – Anne Louise Germaine de Staël, French writer (b. 1766)
July 18 – Jane Austen, English novelist (b. 1775)
July 19 – John Palmer, Bath architect (b. c. 1738)
October 16 – Manuel Piar, Venezuelan military leader (b. 1774)
November 14 – Policarpa Salavarrieta, Colombian spy and revolutionary who worked for the Independence of Colombia (b. 1795)
November 30 – Jean-Baptiste-Melchior Hertel de Rouville, Canadian politician (b. 1748)
December 7 – William Bligh, Captain of the Bounty, Governor of New South Wales (b. 1754)