Below, the events of the First World War have the "WWI" prefix.
- March 7 – In Munich, German automobile company BMW (Die Bayerischen Motoren Werke) 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
- March 24 – French ferry SS Sussex is torpedoed by SM UB-29 in the English Channel, with at least 50 killed (including the composer Enrique Granados), resulting on May 4 in the Sussex Pledge by Germany to the United States, suspending its intensified submarine warfare policy.
- 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 (modern-day Wrigley Field), defeating the Cincinnati Reds 7–6 in 11 innings.
- April 22 – The Chinese troop transport SS Hsin-Yu 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 (800 nautical miles (1,500 km; 920 mi)) 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 (Irish) 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.
- 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 80 miles (130 km) 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 (later renamed Boeing).
- 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.
Troops from New Zealand during WWI.
- 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.
- The cancelled 1916 Summer Olympics in Berlin, Germany.
- Food is rationed in Germany.
- Ferdinand de Saussure's Cours de linguistique générale is collected posthumously and published.
- Oxycodone, a narcotic painkiller closely related to codeine is first synthesized in Germany.
- Ernst Rüdin publishes his initial results on the genetics of schizophrenia.
- Louis Enricht claims he has a substitute for gasoline.
- Rodeo's first side-delivery bucking chute is designed and made by the Bascom boys (Raymond, Mel, Earl) and their father John W. Bascom at Welling, Alberta, Canada.
- Gustav Holst composes The Planets, Opus 32.
- Bray Studios begins the Farmer Al Falfa series, the first of the Terrytoons.
- The Society of Motion Picture and Television Engineers is founded in the United States as the Society of Motion Picture Engineers.
- Ishikawajima Automobile Manufacturing, as predecessor of Isuzu, a truck brand in Japan, that founded.