1908 (MCMVIII) was a leap year starting on Wednesday of the Gregorian calendar and a leap year starting on Tuesday of the Julian calendar, the 1908th year of the Common Era (CE) and Anno Domini (AD) designations, the 908th year of the 2nd millennium, the 8th year of the 20th century, and the 9th year of the 1900s decade. As of the start of 1908, the Gregorian calendar was 13 days ahead of the Julian calendar, which remained in localized use until 1923. This is the longest year in either the Julian or Gregorian calendars, having a duration of 31622401.38 seconds of Terrestrial Time (or ephemeris time), measured according to the definition of mean solar time.
Brazilian supercentenarian Inah Canabarro Lucas was the last known person born in 1908 when she died on April 30, 2025.
January 1 – The British Nimrod Expedition led by Ernest Shackleton sets sail from New Zealand for Antarctica on the Nimrod.
January 3 – A total solar eclipse is visible in the Pacific Ocean and is the 46th solar eclipse of Solar Saros 130.
January 13 – A fire breaks out at the Rhoads Opera House in Boyertown, Pennsylvania, killing 171 people.
January 15 – Alpha Kappa Alpha, the first race inclusive sorority is founded on the campus of Howard University in Washington, D.C.
January 24 – Robert Baden-Powell's Scouting for Boys begins publication in London. The book eventually sells over 100 million copies, and effectively begins the worldwide Boy Scout movement.
February 1 – Lisbon Regicide: King Carlos I of Portugal and Prince Luis Filipe are shot dead in Lisbon.
February 3 – Panathinaikos A.O., a well-known professional multi-sports club of Greece, is founded in Athens.
February 12 – The first around-the-world car race, the 1908 New York to Paris Race, begins.
February 29 – The State Normal and Industrial School for Women, precursor to James Madison University, is founded in Harrisonburg, Virginia.
A 40,000-year-old Neanderthal boy skeleton is found at Le Moustier in southwest France, by Otto Hauser.
Arthur Mee's The Children's Encyclopædia begins publication in London.
Clifford W. Beers's memoir of psychiatric abuse, A Mind That Found Itself, was published.
The Pretoria branch of Transvaal University College, precursor to the University of Pretoria, is established.
The Collinwood school fire near Cleveland, Ohio kills 175.
Bank of Communications, a major financial services provider in China, is founded in Beijing.
March 9 – Football Club Internazionale is founded in Milan, Italy.