- Jan 24 Lieutenant General Robert Baden-Powell publishes "Scouting for Boys" as a manual for self-instruction in outdoor skills and self-improvement. The book becomes the inspiration for the Scout Movement.
- Feb 1 King Carlos I of Portugal and his heir, Prince Luis Filipe are assassinated by Republican sympathizers in Terreiro do Paco, Lisbon
- May 26 At Masjed Soleyman (مسجد سليمان) in southwest Persia, the first major commercial oil strike in the Middle East is made, rights acquired by the United Kingdom
- Jun 30 Tunguska Event: a giant fireball most likely caused by the air burst of a large meteoroid or comet impacts in Siberia
- Jul 26 United States Attorney General Charles Joseph Bonaparte issues an order to immediately staff the Office of the Chief Examiner (later renamed the Federal Bureau of Investigation)
- Aug 12 Henry Ford's company builds the first Model T car
- Sep 27 Henry Ford's first Ford Model T automobile leaves the Piquette Plant in Detroit, Michigan
- Oct 1 Henry Ford introduces the Model T car (costs $825)
- Nov 14 Albert Einstein presents his quantum theory of light
- Dec 28 Earthquake strikes Messina, Italy, killing nearly 80,000
"SOS" (· · · – – – · · ·) distress signal becomes the worldwide standard for help
On July 1, 1908
"Sullivan Ordinance" is passed in NYC, making it illegal for a woman to smoke in public places. It was vetoed 2 weeks later by mayor George B. McClellan Jr.
On January 21, 1908