1834
Events
January–March
April–June
July–September
- July 7–10 – Anti-abolitionist riots break out in New York City.
- July 8 – Imam Faisal bin Turki enters Riyadh and upon entering his father's palace, assassinates his father's murderer, Ibrahim Hamza, and his master; Mishari, and becomes the ruler and founder of the Second Saudi State.
- July 15 – The Spanish Inquisition, which began in the 15th century, is suppressed by royal decree.
- July 16 – William Lamb, 2nd Viscount Melbourne succeeds Earl Grey as Prime Minister of the United Kingdom.
- July 24 – The Liberal Wars end in Portugal.
- July 29 – The Office of Indian Affairs is organized in the United States.
- August 1
- *Slavery is abolished in the British Empire, by the Slavery Abolition Act 1833.
- *Construction work begins on the Wilberforce Monument in Kingston Upon Hull.
- August 11–12 – Ursuline Convent riots: A convent of Ursuline nuns is burned near Boston.
- August 12 – In the Empire of Brazil, the Additional Act provides for establishment of the Provincial Legislative Assembly, extinction of the State Council, replacement of the Regency Trina, and introduction of a direct and secret ballot.
- August 14 – The Poor Law Amendment Act in the United Kingdom states that no able-bodied British man can receive assistance, unless he enters a workhouse.
- August 15 – The South Australia Act allows for the creation of a colony there.
- September 11 – The emigrant ship Sybelle out of Cromarty is wrecked off St. Paul Island (Nova Scotia) with the loss of all 316 passengers and all but six of her crew.
- September 13 – The Gleaner newspaper is first published in Jamaica.
- September 18 – Athens becomes Greece's capital city.
October–December
Date unknown
Births
January–June
- January 7 – Johann Philipp Reis, German physicist, inventor
- January 15 – Samuel Arza Davenport, American politician
- January 17 – August Weismann, German evolutionary biologist
- January 20 – Piet Joubert, Boer politician, military commander
- January 25 – Alina Frasa, Finnish ballerina
- February 6 – Edwin Klebs, German-Swiss pathologist who discovered Diphtheria
- February 8 – Dmitri Mendeleev, Russian chemist
- February 9 – Felix Dahn, German author
- February 16 – Ernst Haeckel, German zoologist, philosopher
- February 19 – Charles Davis Lucas, British Victoria Cross recipient
- February 27 – Charles C. Carpenter, American admiral
- March 5 – Félix de Blochausen, 6th Prime Minister of Luxembourg
- March 16 – Sir James Hector, Scottish geologist
- March 17 – Gottlieb Daimler, German engineer, inventor
- March 20 – Charles W. Eliot, American President of Harvard University
- March 23 – Julius Reubke, German composer
- March 24
- * John Wesley Powell, American explorer
- * William Morris, English poet, artist
- April 2 – Paškal Buconjić, Herzegovinian Catholic bishop
- April 26 – Artemus Ward, American humorist
- May 20 – Albert Niemann, German chemist
- May 23 – Carl Heinrich Bloch, Danish sculptor
- June 19 – Charles Spurgeon, English Baptist preacher
July–December
- July 2 – Hendrick Peter Godfried Quack, Dutch economist, historian
- July 4 – Christopher Dresser, British designer influential in the Anglo-Japanese style
- July 10 – James McNeill Whistler, American painter, etcher
- July 19 – Edgar Degas, French painter
- July 2 – Frédéric Auguste Bartholdi, French sculptor
- July 27 – Miguel Grau Seminario, Peruvian admiral
- August 4 – John Venn, British mathematician
- August 22 – Samuel Pierpont Langley, American astronomer, physicist, and aeronautics pioneer
- August 31 – Amilcare Ponchielli, Italian composer
- Heinrich von Treitschke German historian, political writer, and National Liberal member of the Reichstag during the time of the German Empire.
- September 17 – Robert Simpson, Scottish-Canadian businessman
- September 28 – William Montrose Graham Jr., American general
- September 30 – Louis P. Mouillard, French artist, aviation pioneer
- October 6 – Walter Kittredge, American composer
- October 10 – Aleksis Kivi, Finnish national author
- November 8 – Johann Karl Friedrich Zöllner, German astrophysicist
- November 13 – Ignacio Manuel Altamirano, Mexican writer
- November 19 – Georg Hermann Quincke, German physicist
- November 21 – Hetty Green, American businesswoman
- November 28 – Sophronia Farrington Naylor Grubb, American activist
- December 16 – Léon Walras, French economist
- December 24 – Augustus George Vernon Harcourt, English chemist
Date unknown
Deaths
January–June
- January 6 – Richard Martin, Irish founder of the Society for the Prevention of Cruelty to Animals
- January 12 – William Grenville, 1st Baron Grenville, Prime Minister of the United Kingdom
- January 17 – Giovanni Aldini, Italian physicist
- February 2 – Lorenzo Dow, American minister
- February 4 – Amélie-Julie Candeille, French composer, librettist, writer, singer, actress, comedian, and instrumentalist
- February 12 – Friedrich Schleiermacher, German theologian and philosopher
- February 18 – William Wirt, 9th United States Attorney General
- February 23 – Karl Ludwig von Knebel, German poet
- March 2 – José Cecilio del Valle, first President of Central America
- March 30 – Rudolph Ackermann, Anglo-German entrepreneur
- April 5 – Vice-Admiral Sir Richard Goodwin Keats, Governor of Newfoundland
- April 10 – John 'Merino' MacArthur, Australian farmer
- April 11 – John 'Mad Jack' Fuller, English philanthropist, patron of the arts and sciences
- April 29 – Grigore IV Ghica, prince of Wallachia
- May 9 – Turki bin Abdullah bin Muhammad, founder of the First Saudi State
- May 20 – Gilbert du Motier, Marquis de Lafayette, French nobleman, soldier
- May 31 – Shaikh Khalifa bin Salman bin Ahmed Al Khalifa, Deputy Ruler of Bahrain
July–December
- July 12 – David Douglas, Scottish botanist
- July 14 – Edmond-Charles Genêt, French ambassador to the United States during the French Revolution
- July 19 – Károly Hadaly, Hungarian mathematician
- July 25 – Samuel Taylor Coleridge, English writer
- July 26 – Jonathan Jennings, American politician and the first governor of Indiana
- August 1 – Robert Morrison, British Protestant missionary to China
- August 7 – Joseph Marie Jacquard, French inventor
- August 17 – Husein Gradaščević, Bosnian rebel leader
- September 2 – Thomas Telford, Scottish engineer
- September 5 – Thomas Lee, English architect
- September 9 – James Weddell, Antarctic explorer
- September 15 – William H. Crawford, American politician, judge
- September 16 – William Blackwood, Scottish writer
- September 24 – Emperor Pedro I of Brazil
- October 5 – María Josefa Pimentel, Duchess of Osuna
- October 8 – François-Adrien Boieldieu, French composer
- October 11 – William Napier, 9th Lord Napier, British Navy officer, politician and diplomat
- October 21 – Edward Smith-Stanley, 12th Earl of Derby
- October 23 – Fath Ali Shah Qajar, King of Iran
- October 31 – Éleuthère Irénée du Pont, French-American chemical manufacturer
- November 2 – Maria Teresa Poniatowska, Polish aristocrat
- November 27 – Rosalie de Constant, Swiss naturalist
- December 23 – Thomas Malthus, English economist, political philosopher
- December 27 – Charles Lamb, English essayist
- December 31 – João Batista Gonçalves Campos, intellectual leader of the Cabanagem revolt