1878

January–March

 * January 5 – Battle of Shipka Pass IV: Russian and Bulgarian forces defeat the Ottoman Empire.
 * January 9 – Umberto I becomes King of Italy.
 * January 17 – Battle of Philippopolis: Russian troops defeat the Turks.
 * January 23 – Benjamin Disraeli orders the British fleet to the Dardanelles.
 * January 24 – The revolutionary Vera Zasulich shoots at Fyodor Trepov, the Governor of Saint Petersburg.
 * January 28 – The Yale News becomes the first daily college newspaper in the United States.
 * January 31 – Turkey agrees to an armistice at Adrianople.
 * February 2 – Greece declares war on Turkey.
 * February 7 – Pope Pius IX dies after a 31½ year reign (the longest definitely confirmed).
 * February 8 – The British fleet enters Turkish waters and anchors off Istanbul; Russia threatens to occupy Istanbul but does not carry out the threat.
 * February 18 – The Lincoln County War begins in Lincoln County, New Mexico.
 * February 19 – The phonograph is patented by Thomas Edison.
 * February 20 – Pope Leo XIII succeeds Pope Pius IX as the 256th pope.
 * February 23 - Sadguru Shri Gajanan Maharaj appeared at Shegaon, Dist: Buldhana, Maharashtra.
 * February 24 – Anti-Russian demonstrations occur in Hyde Park, London.
 * February 28 – Mississippi State University is created by the Mississippi Legislature (under the name The Agricultural and Mechanical College of the State of Mississippi).
 * March 3 – The Treaty of San Stefano concludes the Russo-Turkish War; Bulgaria and Romania regain their independence from the Ottoman Empire
 * March 24 – The British Royal Navy frigate HMS Eurydice (1843) capsizes in the English Channel, killing all but two of the 319 crew.
 * March 25 – Russia rejects a British proposal to lay the San Stefano treaty before a European congress.
 * March 27 – In anticipation of war with Russia, Disraeli mobilizes the reserves and calls up Indian troops to Malta.

April–June

 * April 20 – The Stawell Gift is run for the first time in Australia.
 * May 2 – The Washburn "A" Mill in Minneapolis explodes, killing 18.
 * May 15 – The Tokyo Stock Exchange is established.
 * May 25 – Gilbert and Sullivan's comic opera H.M.S. Pinafore debuts in London at the Opera Comique with a first run of 571 performances.
 * June 1 – General Postal Union renamed Universal Postal Union (UPU).
 * June 4 – Cyprus Convention: The Ottoman Empire cedes Cyprus to the United Kingdom but retains the nominal title.
 * June 13–July 13 – The Congress of Berlin convenes to discuss the Ottoman Empire.
 * June 15 – Eadweard Muybridge produces the sequence of stop-motion still photographs Sallie Gardner at a Gallop in California, a predecessor of silent film demonstrating that all four feet of a galloping horse are off the ground at the same time.
 * June 20 – U.S. Coastal Survey renamed U.S. Coast and Geodetic Survey.
 * June 22 – Adolf Erik Nordenskiöld leaves Karlskrona on a voyage that will make him the first to navigate the Northern Sea Route, a shipping lane from the Atlantic Ocean to the Pacific Ocean along the Siberian coast.

July–September

 * July 4 – A match race between champion thoroughbred racehorses Ten Broeck and Mollie McCarty draws more than 30,000 fans to Louisville and inspires the folk song, Molly and Tenbrooks.
 * July 13 – The Treaty of Berlin makes Serbia, Montenegro and Romania completely independent, confirms the autonomy of Bulgaria, makes Cyprus a British possession and allows Austria-Hungary to garrison the Bosnia Vilayet.
 * July 26 – In California, the poet and American West outlaw calling himself "Black Bart" makes his last clean getaway when he steals a safe box from a Wells Fargo stagecoach. The empty box is found later with a taunting poem inside.
 * August 7 – The Salvation Army "foundation deed" is signed.
 * August 9 – The Wallingford Tornado of 1878, the deadliest tornado in Connecticut history, destroys the town of Wallingford, killing 34 people and injuring 70 or more.
 * August 26 – Uyedineniya Island is discovered in the Kara Sea by Norwegian explorer Captain Edvard Holm Johannesen.
 * September 3 – Over 640 die when the crowded pleasure boat SS Princess Alice (1865) collides with the Bywell Castle in the River Thames.
 * September 12 – Cleopatra's Needle is erected in London, having arrived in England on January 21.
 * September 20 – The Hindu, an Indian newspaper, is founded.
 * September 30 – The ship Priscilla arrives in Hawaii from Funchal, Madeira, marking the beginning of the Portuguese immigration to the Hawaiian Islands (1878–1913).

October–December

 * October 1 – Virginia Polytechnic Institute and State University (Virginia Tech) opens as Virginia Agricultural and Mechanical College in the United States.
 * October 14 – The world's first recorded floodlit football fixture is played at Bramall Lane in Sheffield, England.
 * October 17 – John A. Macdonald returns to office as Prime Minister of Canada.
 * October 31 – A fire destroys the Eldkvarn gristmill mill in Stockholm, Sweden.
 * November 17 – The first assassination attempt is made against Umberto I of Italy by anarchist Giovanni Passannante, armed with a dagger. The King survived with a slight wound in one arm. Prime minister Benedetto Cairoli blocks the aggressor, receiving a leg injury.
 * November 21 – The Second Anglo-Afghan War commences when the British attack Ali Masjid in the Khyber Pass.
 * November 26 – American-born artist James McNeill Whistler's libel case against English critic John Ruskin over a review of the painting Nocturne in Black and Gold – The Falling Rocket (in which Whistler is described as "flinging a pot of paint in the public's face") is decided in the High Court of Justice in London. Whistler wins a farthing in nominal damages and only half of the costs, leading to his bankruptcy, and alienates patrons.
 * December 7 — The United States territory of New Mexico is linked to the rest of the nation by railroad for the first time as the Atchison, Topeka and Santa Fe Railway inaugurates a newly completed line through the Raton Pass.
 * December 25 — Stella Maris Church in Sliema, Malta becomes a parish - seceding from the Parish of St. Helen's in Birkirkara.

Date unknown

 * U.S. arbitration rejects Argentine claims to Paraguay's part of the Chaco region.
 * Otto von Bismarck abandons his Kulturkampf and forces through legislation outlawing the Social Democrats.
 * 10-year Nauruan Tribal War breaks out.
 * Yellow fever in the Mississippi Valley kills over 13,000.
 * Foundation of:
 * Nainital Cantonment.
 * The Buchan School, Isle of Man.
 * The Johns Hopkins University Press, America's oldest university press.
 * Geiger (corporation), formed as Geiger Brothers.
 * The following English Association football clubs:
 * Everton Football Club, formed as St Domingo.
 * Grimsby Town F.C., formed as Grimsby Pelham.
 * Ipswich Town Football Club, formed as amateur club Ipswich A.F.C. They will not turn professional until 1936.
 * Newton Heath Lancashire and Yorkshire Railway Football Club, the team that will become Manchester United.
 * West Bromwich Albion F.C..
 * Leo Tolstoy's novel Anna Karenina is published complete in book form in Moscow.
 * Lester Allan Pelton produces the first operational Pelton wheel.
 * Death of last confirmed Cape lion.
 * Remington, in the United States, introduce their No. 2 typewriter, the first with a shift key enabling production of lower as well as upper case characters.

January–June

 * January 4
 * A. E. Coppard, English short story writer and poet (d. 1957)
 * Augustus John, Welsh-born painter (d. 1961)
 * January 6 – Carl Sandburg, American poet and historian (d. 1967)
 * January 9 – John B. Watson, American psychologist (d. 1958)
 * January 12 – Ferenc Molnár, Hungarian-born author (d. 1952)
 * January 20 – Finlay Currie, Scottish actor (d. 1968)
 * January 22 – Constance Collier, English stage & screen actress (d. 1955)
 * January 23 – Rutland Boughton, English composer (d. 1960)
 * January 25 – Ernst Alexanderson, Swedish-born television pioneer (d. 1975)
 * February 1 – Milan Hodža, Slovak politician, champion of regional integration in Europe (d. 1944)
 * February 2 – Alfréd Hajós, Hungarian swimmer and architect (d. 1955)
 * February 5 – André Citroën, French automobile manufacturer (d. 1935)
 * February 8 – Martin Buber, Austrian philosopher (d. 1965)
 * February 14 – Hirota Koki, Prime Minister of Japan (d. 1948)
 * February 16
 * Giacomo "James" Colosimo, Italian-born American gangster (d. 1920)
 * Selim Palmgren, Finnish composer (d. 1951)
 * February 21 – The Mother (Mirra Alfassa), multi-origined spiritual leader and founder of Auroville in India (d. 1973)
 * February 26 – Emmy Destinn, Czech soprano (d. 1930)
 * February 28 – Pierre Fatou, French mathematician (d. 1929)
 * March 4
 * Egbert Van Alstyne, United States songwriter and pianist (d. 1951)
 * Peter D. Ouspensky, Russian philosopher (d. 1947)
 * Arishima Takeo, Japanese novelist, short-story writer and essayist (d. 1923)
 * March 5 – P. D. Ouspensky, Russian mathematician (d. 1947)
 * March 16 – Clemens August Graf von Galen, German Catholic cardinal (d. 1946)
 * March 22 – Michel Théato, Luxembourg athlete (d. 1919)
 * March 26 – Henry Gullett, Australian politician (d. 1940)
 * March 31 – Jack Johnson, American boxer (d. 1946)
 * April 1 – C. Ganesha Iyer, Ceylon Tamil Philologist (d. 1958)
 * April 4 – Stylianos Lykoudis, Greek admiral (d. 1958)
 * April 6 – Erich Mühsam, German author (d. 1934)
 * April 24 – Jean Crotti, Swiss artist (d. 1958)
 * April 28
 * Lionel Barrymore, American actor (d. 1954)
 * Willem Mengelberg, Dutch conductor (d. 1951)
 * May 3 – Jean Chiappe, French civil servant (d. 1940)
 * May 10 – Gustav Stresemann, Chancellor of Germany, recipient of the Nobel Peace Prize (d. 1929)
 * May 18 – Dr. Prescott, American doctor, explorer, and philanthropist (d. 1938)
 * May 21 – Glenn H. Curtiss, American aviation pioneer (d. 1930)
 * May 25 – Bill Robinson, African American tap dancer (d. 1949)
 * May 27 – Anna Cervin, Swedish artist (d. 1972)
 * May 28 – Paul Pelliot, French sinologist (d. 1945)
 * June 1 – John Masefield, English poet and novelist (d. 1967)
 * June 3 – Barney Oldfield, American automobile racer and pioneer (d. 1946)
 * June 5 – Pancho Villa, Mexican revolutionary (d. 1923)
 * June 12 – James Oliver Curwood, American writer and conservationist (d. 1927)
 * June 20 – Will Mastin, American vaudevillian (d. 1975)
 * June 27 – He Xiangning, Chinese revolutionary, feminist, politician, painter and poet (d. 1972)

July–December

 * July 3 – George M. Cohan, American singer, dancer, composer, actor, and writer (d. 1942)
 * July 10 – Otto Freundlich, German painter and sculptor (d. 1943)
 * July 12
 * Claude C. Bloch, American admiral (d. 1967)
 * Peeter Põld, Estonian pedagogical scientist and politician (d. 1930)
 * July 24 – Edward Plunkett, Baron Dunsany, Irish author (d. 1957)
 * August 2 – Princess Ingeborg of Denmark, Princess of Sweden (d. 1958)
 * August 4 – Ernest Lundeen, American lawyer and politician (d. 1940)
 * August 9 – Eileen Gray, Irish architect and furniture designer (d. 1976)
 * August 10 – Alfred Döblin, German writer (d. 1957)
 * August 13 – Harold Clarke Goddard, American professor and Shakespearean scholar (d. 1950)
 * August 19 – Manuel Luis Quezon, 2nd President of the Philippines (d.1944)
 * August 28 – George Whipple, American scientist, recipient of the Nobel Prize in Physiology or Medicine (d. 1976)
 * August 31 – Frank Jarvis, American athlete (d. 1933)
 * September 2 – Werner von Blomberg, German field marshal (d. 1946)
 * September 5 – Robert von Lieben, Austrian physicist (d. 1913)
 * September 9 – Sergio Osmena, 4th President of the Philippines (d. 1961)
 * September 13 – Matilde Moisant, American pilot (d. 1964)
 * September 14 – Ion Farris, American politician, former Speaker of the Florida House of Representatives (d. 1934)
 * September 18 – James O. Richardson, American admiral (d. 1974)
 * September 20 – Upton Sinclair, American writer (d. 1968)
 * September 22 – Yoshida Shigeru, Prime Minister of Japan (d. 1967)
 * September 24 – C. F. Ramuz, Swiss writer (d. 1947)
 * October 1 – Othmar Spann, Austrian philosopher and economist (d. 1950)
 * October 9 – Robert Warwick, American stage & screen actor (d. 1964)
 * October 16 – Maxie Long, American athlete (d. 1959)
 * October 29 – Alexander von Falkenhausen, German general (d. 1966)
 * November 1 – Carlos Saavedra Lamas, Argentine politician, recipient of the Nobel Peace Prize (d. 1959)
 * November 14
 * Inigo Campioni, Italian admiral (d. 1944)
 * Julie Manet, French painter (d. 1966)
 * Leopold Staff, Polish poet (d. 1957)
 * November 17 – Grace Abbott, American social worker and activist (d. 1939)
 * November 23
 * Ernest Joseph King, Commander in Chief, United States Fleet and Chief of Naval Operations (COMINCH-CNO) during World War II (d. 1956)
 * Frank Pick, British transport administrator and designer (d. 1941)
 * December 1 – Nathaniel Baldwin, American inventor and  a supporter of the early Mormon fundamentalist movement (d. 1961)
 * December 10 – C. Rajagopalachari, Indian politician and freedom-fighter. (d. 1972)
 * December 18 – Joseph Stalin, leader of the Soviet Union (d. 1953)
 * December 25
 * Louis Chevrolet, Swiss-born race driver and automobile builder (d. 1941)
 * Joseph Schenck, Russian-born American film executive (d. 1961)
 * December 28 – Nikolai Bryukhanov, Soviet statesman and political figure who served as People's Commissar of Finances (d. 1938)
 * December 31
 * Elizabeth Arden, Canadian-born beautician and cosmetics entrepreneur (d. 1966)
 * Horacio Quiroga, Argentine writer (d. 1937)

January–June

 * January 8 – Nikolay Nekrasov, Russian poet (b. 1821)
 * January 9 – King Victor Emmanuel II of Italy (b. 1820)
 * January 18 – Antoine César Becquerel, French scientist (b. 1788)
 * February 7 – Pope Pius IX (b. 1792)
 * February 11 – Gideon Welles, American politician (b. 1802)
 * February 19 – Charles-François Daubigny, French painter (b. 1817)
 * February 26 – Angelo Secchi, Italian astronomer (b. 1818)
 * March 8 – Archduke Franz Karl of Austria (b. 1802)
 * March 20 – Julius von Mayer, German physician and physicist and one of the founders of thermodynamics (b. 1814)
 * March 27 – George Gilbert Scott, British architect (b. 1811)
 * April 8 – Henrietta Treffz, soprano, first wife of Johann Strauss II (b. 1818)
 * April 11 – Robert Wentworth Little, British occultist (b. 1840)
 * April 12 – William M. Tweed, American politician (b. 1823)
 * April 25 – Anna Sewell, English author (b. 1820)
 * May 12 – Anselme Payen, French chemist (b. 1795)
 * May 13 – Joseph Henry, American scientist (b. 1797)
 * May 14 – Ōkubo Toshimichi, Japanese samurai and later leader of the Meiji restoration (b. 1830)
 * May 28 – John Russell, 1st Earl Russell, Prime Minister of the United Kingdom (b. 1792)
 * June 6
 * Robert Stirling, Scottish clergyman and inventor (b. 1790)
 * Achille Baraguey d'Hilliers, Marshal of France (b. 1795)
 * Porter Rockwell, Mormon bodyguard (b. 1815)
 * June 12
 * George V of Hanover (b. 1819)
 * Hendrik Jut, Dutch murderer (b. 1851)
 * June 27 – Sidney Breese, U.S. senator from Illinois known as the "father of the Illinois Central Railroad" (b. 1800)

July–December

 * July 1 – Catherine Winkworth, English translator of hymns (b. 1827)
 * July 17 – Aleardo Aleardi, Italian poet (b. 1812)
 * July 23 – Carl Freiherr von Rokitansky, Bohemian pathologist, philosopher and politician (b. 1804)
 * August 13 – Henry James Montague, English-born actor (b. 1844)
 * August 16 – Richard Upjohn, English-American architect (b. 1802)
 * August 26 – Mariam Baouardy, Syrian Melkite Greek Catholic nun, canonized (b. 1846)
 * August 30 – James Geiss, English businessman (b. 1820)
 * September 7 – Mehmed Ali Pasha, Prussian-born Ottoman military leader (b. 1827)
 * October 20 – Hiram Paulding, American admiral (b. 1797)
 * November 20 – William Thomas (Islwyn), Welsh poet (b. 1832)
 * November 28 – Orson Hyde, American religious leader (b. 1805)
 * December 10 – Henry Wells, American businessman (b. 1805)
 * December 14 – Princess Alice, Grand Duchess of Hesse and by Rhine (b. 1843)
 * December 25 – Henry K. Hoff, American admiral (b. 1809)

In fiction

 * The Doctor Who novel Imperial Moon takes place in this year.