== EventsBelow, the events of the First World War have the "WWI" prefix.
- January 1 - The British Royal Army Medical Corps carries out the first successful blood transfusion, using blood that had been stored and cooled.
- January 9 - WWI: Gallipoli Campaign: The last British troops are evacuated from Gallipoli, as the Ottoman Empire prevails over a joint British and French operation to capture Istanbul.
- January 10 - WWI: Erzurum Offensive: Russia defeats the Ottoman Empire.
- January 13 - WWI: Battle of Wadi: Ottoman Empire forces defeat the Allied British, during the Mesopotamian campaign in modern-day Iraq.
- January 24
- * In Browning, Montana, the temperature drops from +6.7 °C to -48.8 °C in one day, the greatest change ever on record for a 24-hour period.
- * Brushaber v. Union Pacific Railroad Co.: The Supreme Court of the United States upholds the national income tax.
- January 29 - WWI: Paris is bombed by German zeppelins.
- January 31 - WWI: An attack is planned on Verdun, France.
- February 3 - Parliament buildings in Ottawa, Ontario, Canada burn down.
- February 9 - 6.00 p.m. - Tristan Tzara "founds" the art movement Dadaism.
- February 11
- * Emma Goldman is arrested, for lecturing on birth control in the United States.
- * The Baltimore Symphony Orchestra presents its first concert in the United States.
- * The Romanian football club Sportul Studențesc is founded in Bucharest.
- February 12 - WWI - Battle of Salaita Hill : South African and other British Empire troops fail to take a German East African defensive position.
- February 21 - WWI: The Battle of Verdun begins in France.
- March 7 - In Munich, German automobile company BMW is founded.
- March 8-9 - Mexican Revolution: Pancho Villa leads about 500 Mexican raiders in an attack against Columbus, New Mexico, killing 12 U.S. soldiers. A garrison of the U.S. 13th Cavalry Regiment fights back and drives them away.
- March 10 - The McMahon–Hussein Correspondence concludes with an understanding that the United Kingdom would recognise Arab independence in return for Hussein bin Ali, Sharif of Mecca, launching the Arab Revolt against the Ottoman Empire.
- March 15 - United States President Woodrow Wilson sends 12,000 United States troops over the U.S.–Mexico border to pursue Pancho Villa; the 13th Cavalry regiment enters Mexican territory.
- March 16 - Mexican Revolution: The U.S. 7th and 10th Cavalry regiments under John J. Pershing cross the border, to join the hunt for Villa.
- March 22
- * The temporary Emperor of China, Yuan Shikai, abdicates the throne, and the Republic of China is restored once again.
- * J. R. R. Tolkien marries Edith Bratt in England.
- March 24 - French ferry is torpedoed by in the English Channel, with at least 50 killed, resulting on May 4 in the Sussex Pledge by Germany to the United States, suspending its intensified submarine warfare policy.
Aprildistributed during the Easter Rising
- * The toggle light switch is invented, by William J. Newton and Morris Goldberg.
- * Korea Tungsten was founded in Daegu, as predecessor of leading steel product in Asia, POSCO.
- April 11 - WWI: The Egyptian Expeditionary Force begins the occupation of the Sinai Peninsula.
- April 20 - The Chicago Cubs play their first game at Weeghman Park, defeating the Cincinnati Reds 7–6 in 11 innings.
- April 22 - The Chinese troop transport capsizes off the Chinese coast; at least 1,000 are killed.
- April 24-30 - The Easter Rising occurs in Ireland. Members of the Irish Republican Brotherhood proclaim an Irish Republic, and the Irish Volunteers and Irish Citizen Army occupy the General Post Office and other buildings in Dublin, before surrendering to the British Army.
- April 24-May 10 - Voyage of the James Caird: An open boat journey from Elephant Island in the South Shetland Islands to South Georgia in the southern Atlantic Ocean is undertaken by Sir Ernest Shackleton and five companions, to obtain rescue for the main body of the Imperial Trans-Antarctic Expedition, following the loss of its ship Endurance.
- April 27 - WWI: Gas attack at Hulluch in France: The 47th Brigade, 16th Division is decimated, in one of the most heavily concentrated German gas attacks of the war.
- April 29 - WWI - Mesopotamian campaign: The Siege of Kut ends with the surrender of British forces to the Ottoman Empire, at Kut-al-Amara on the Tigris in Basra Vilayet.
May-June 1:Battle of Jutland between Allies and Germany
- May 16
- * United States Marines invade the Dominican Republic.
- * Britain and France conclude the secret Sykes–Picot Agreement, which is to divide Arab areas of the Ottoman Empire, following the conclusion of WWI and the partitioning of the Ottoman Empire, into French and British spheres of influence.
- May 31-June 1 - WWI: Battle of Jutland, between the British Royal Navy's Grand Fleet and the Imperial German Navy's High Seas Fleet in the North Sea, the war's only large-scale clash of battleships. The result is tactically inconclusive, but British dominance of the North Sea is maintained.
- June 4 - WWI: The Brusilov Offensive, the height of Russian operations in the war, begins with their breaking through Austro-Hungarian lines.
- June 5 - WWI: sinks, having hit a mine off the Orkney Islands, Scotland, with Lord Kitchener aboard.
- June 10: The Arab Revolt against the Ottoman Empire, to create a single unified Arab state spanning from Aleppo to Aden, is formally declared by Hussein bin Ali, Sharif of Mecca.
- June 15 - U.S. President Woodrow Wilson signs a bill incorporating the Boy Scouts of America.
July-November 18:Battle of the Somme between British and German.
- July 1-November 18 - WWI: Battle of the Somme, opening with explosion of the British Y Sap mine and the Battle of Albert: More than one million soldiers die, with 57,470 British Empire casualties on the first day, 19,240 of them killed, the British Army's bloodiest day. The immediate result is tactically inconclusive.
- July 1-12 - Jersey Shore shark attacks of 1916: At least one shark attacks 5 swimmers along of New Jersey coastline, resulting in 4 deaths and the survival of one youth, who requires limb amputation. This event is the inspiration for author Peter Benchley, over half a century later, to write Jaws.
- July 2 - WWI: Battle of Erzincan - Russian forces defeat troops of the Ottoman Empire in Armenia.
- July 15 - In Seattle, William Boeing incorporates Pacific Aero Products.
- July 15-19 - WWI: Battle of Delville Wood - 766 men from the South African Brigade are killed, in South Africa's biggest loss during the First World War.
- July 19-20 - WWI: Battle of Fromelles - An attack by Australian and British troops is repulsed by the German army, with heavy casualties.
- July 22 - Preparedness Day Bombing: In San Francisco, a bomb explodes on Market Street during a Preparedness Day parade, killing 10 and injuring 40; Warren Billings and Tom Mooney are later wrongly convicted of it.
- July 26 - WWI: East African Campaign - The German armed ship SMS Graf von Goetzen scuttles herself on Lake Tanganyika.
- July 29 - Matheson Fire: In Ontario, Canada, a lightning strike ignites a forest fire that destroys the towns of Cochrane and Matheson, killing 233.
- July 30 - German agents cause the Black Tom explosion in Jersey City, New Jersey, an act of sabotage destroying an ammunition depot and killing at least 7 people.
- August - Robert Baden-Powell publishes The Wolf Cub's Handbook in the U.K., establishing the basis of the junior section of the Scouting movement, the Wolf Cubs.
- August 3-5 - WWI: Sinai and Palestine Campaign - Battle of Romani: British Imperial troops secure victory over a joint Ottoman-German force.
- August 7 - WWI:
- * Portugal joins the Allies.
- * French and British forces make an unopposed entry into German-controlled Togoland; on December 27 the country is partitioned between the two allies.
- August 9 - Lassen Volcanic National Park is established in California.
- August 15 - Club Atlas is founded as an association football club in Guadalajara, Mexico, by English-educated players.
- August 16 - The Migratory Bird Treaty between Canada and the United States is signed.
- August 17 - WWI: The Treaty of Bucharest is signed secretly between Romania and the Entente Powers, stipulating the conditions under which Romania agrees to join the war on their side, particularly territorial promises in Austria-Hungary.
- August 21 - WWI: Peru declares neutrality.
- August 25 - U.S. President Woodrow Wilson signs legislation, creating the National Park Service.
- August 27 - WWI: The Kingdom of Romania declares war on the Central Powers, entering the war on the side of the Allies.
- August 28 - WWI:
- * Germany declares war on Romania.
- * Italy declares war on Germany.
- August 29 - The United States passes the Philippine Autonomy Act.
- August 30 - The crew of the Imperial Trans-Antarctic Expedition's is rescued from Elephant Island.
- September 1 - Bulgaria declares war on Romania, going on to take Dobruja.
- September 2 - WWI: British pilot Leefe Robinson becomes the first to shoot down a German airship over Britain.
- September 4 - WWI: East African Campaign - Dar es Salaam surrenders to British Empire forces, securing them control of the Central Line of railway through German East Africa.
- September 5 - D. W. Griffith's film Intolerance: Love's Struggle Through the Ages is released in the United States.
- September 6 - The first true self-service grocery store, Piggly Wiggly, is founded in Memphis, Tennessee, by Clarence Saunders, opening 5 days later.
- September 11 - A mechanical failure causes the central span of the Quebec Bridge, a cantilever-type structure, to crash into the Saint Lawrence River for the second time, killing 13 workers.
- September 13 - Mary, a circus elephant, is hanged in the town of Erwin, Tennessee for killing her handler, Walter "Red" Eldridge.
- September 15-22 - WWI - Battle of Flers–Courcelette, France: The battle is significant for the first use of the tank in warfare; also for the debut of the Canadian and New Zealand Divisions in the Battle of the Somme.
- September 19 - WWI: East African Campaign - Belgian troops occupy Tabora in German East Africa.
- September 27 - Iyasu V of Ethiopia is deposed in a palace coup, in favour of his aunt Zewditu.