- March 3 - In Sweden, a time bomb destroys the office of Norrskenflamman newspaper of Swedish communists - 5 dead
- March 5- Members of Soviet politbiuro: Stalin, Molotov, Lazar Kaganovich, Mikhail Kalinin, Kliment Voroshilov and Lavrenty Beria himself, signed prepared by Beria order of execution of 25,700 Polish intelligentsia, including 14,700 Polish POW, known also as Katyn massacre.
- March 12 - Soviet Union and Finland sign a peace treaty in Moscow ending the Winter War. Finns, and the World opinion, shocked by the harsh terms.
- March 18 - World War II: Axis powers - Adolf Hitler and Benito Mussolini meet at Brenner Pass in the Alps and agree to form an alliance against France and the United Kingdom.
- April 7 - Booker T. Washington becomes the first African American to be depicted on a United States postage stamp.
- April 9 - World War II: Germany invades Denmark and Norway in operation Weserübung. The British campaign in Norway is simultaneously commenced.
- November 1 - French children discover Lascaux caves
- November 5 - U.S. presidential election, 1940: Democrat incumbent Franklin D. Roosevelt defeats Republican challenger Wendell Willkie and becomes the United States' first third-term president.
- November 7 - In Washington, the middle section of the Tacoma Narrows Bridge collapses in a windstorm, a mere four months after the bridge's completion (it opened to traffic on July 1, 1940 as the third-longest suspension bridge in the world).
- November 11 - World War II: Battle of Taranto - The Royal Navy launches the first aircraft carrier strike in history, on the Italian fleet at Taranto.
- November 11 - World War II: The German Hilfskreuzer (cruiser) Atlantis captures top secret British mail, and sends it to Japan
- November 11 - Armistice Day Blizzard: An unexpected blizzard kills 144 in U.S. Midwest.
- November 14 - World War II: In England, the city of Coventry is destroyed by 500 German Luftwaffe bombers (150,000 fire bombs, 503 tons of high explosives, 130 parachute mines leveled 60,000 of the city's 75,000 buildings; 568 people were killed).
- November 16 - World War II: In response to Germany leveling Coventry two days before, the Royal Air Force begins to bomb Hamburg (by war's end, 50,000 Hamburg residents died from Allied attacks).
- November 18 - World War II: German leader Adolf Hitler and Italian Foreign Minister Galeazzo Ciano meet to discuss Benito Mussolini's disastrous invasion of Greece.
- November 20 - World War II: Hungary, Romania and Slovakia join the Axis Powers.
- November 27 - In Romania, coup leader General Ion Antonescu's Iron Guard arrests and executes over 60 of exiled king Carol II of Romania's aides. Among the dead is former minister and acclaimed historian Nicolae Iorga.
- January 14 - Julian Bond, civil rights activist (cofounder of the Student Nonviolent Coordinating Committee, chairman of NAACP board of directors)
- January 20 - Carol Heiss, Olympic figure skating gold medalist
- January 22 - John Hurt, actor
- February 2 - David Jason, actor
- February 3 - Fran Tarkenton, Football Hall of Famer
- February 4 - George Romero, horror movie writer, producer, director
- February 5 - H.R. Giger, artist
- February 6 - Tom Brokaw, news anchorman
- February 6 - Jimmy Tarbuck, comedian
- February 8 - Ted Koppel, journalist
- February 8 - Joe South, American singer/songwriter
- February 19 - Smokey Robinson, musician
- February 20 - Jimmy Greaves, footballer
- February 24 - Denis Law, footballer
- February 25 - Ron Santo, baseball player
- February 28 - Mario Andretti, automobile driver
- February 29 - Edward Frederick Benson, American writer
- March 7 - Rudi Dutschke, student leader (d. 1979)
- March 7 - Daniel J. Travanti, actor
- March 9 - John Cale, composer, musician
- March 9 - Raúl Juliá, actor (d. 1994)
- March 10 - Dean Torrence, musician ("Jan and Dean")
- March 10 - Chuck Norris, actor, martial arts practitioner
- March 12 - Al Jarreau, singer
- March 15 - Phil Lesh of The Grateful Dead
- March 16 - Bernardo Bertolucci, Italian writer and film director
- March 17 - Mark White, former governor of Texas
- March 22 - Haing S. Ngor, actor (d. 1996)
- March 24 - Bob Mackie, costume designer
- March 25 - Anita Bryant, entertainer
- March 26 - Spiridon Louis, Greek marathon runner
- March 30 - Astrud Gilberto, singer
- April 1 - Wangari Maathai, environmentalist
- April 2 - Penelope Keith, actress
- April 12 - Herbie Hancock, jazz musician
- April 16 - Queen Margaret II of Denmark
- April 20 - George Takei, actor (Star Trek)
- April 25 - Al Pacino, actor (The Godfather, Scarface, Scent of a Woman)
- April 26 - Giorgio Moroder, composer
- May 1 - Elsa Peretti, jewelry designer
- May 8 - Ricky Nelson, pop singer, (d. 1985)
- May 9 - James L. Brooks, producer, writer
- May 11 - Juan Downey, video artist (d. 1993)
- May 20 - Stan Mikita, Hockey Hall of Famer
- May 20 - Sadaharu Oh, baseball star
- May 29 - Farooq Leghari, former President of Pakistan
- June 1 - René Auberjonois, actor (M*A*S*H, Star Trek: Deep Space Nine)
- June 16 - Neil Goldschmidt, governor of Oregon
- June 20 - John Mahoney, actor
- June 23 - Adam Faith, English singer and actor (d. 2003)
- June 23 - Lord Irvine of Lairg, British lawyer and Lord Chancellor
- June 23 - Wilma Rudolph, American runner
- July 7 - Ringo Starr, English drummer (Beatles)
- July 13 - Patrick Stewart, actor (Star Trek: The Next Generation, X-Men)
- July 18 - Joe Torre, baseball player, manager
- July 26 - Mary Jo Kopechne, congressional staffer for Edward Kennedy (d. 1969)
- July 27 - Bharati Mukherjee, Indian-American novelist
- August 3 - Martin Sheen, American actor
- August 7 - Jean-Luc Dehaene, Prime Minister of Belgium
- August 20 - Rubén Hinojosa, American politician
- September 12 - Mickey Lolich, baseball pitcher
- September 14 - Larry Brown, NBA basketball coach
- October 9 - John Lennon, English musician and singer (Beatles) (d. 1980)
- October 13 - Pharoah Sanders, jazz saxophonist
- October 14 - Cliff Richard, English pop singer
- October 23 - Pelé, Brazilian football legend
- October 25 - Bobby Knight, NCAA basketball coach
- November 1 - Ramesh Chandra Lahoti, Chief Justice of India
- November 15 - Sam Waterston, actor (Law & Order)
- November 25 - Joe Gibbs, Football Hall of Fame coach
- November 27 - Bruce Lee, martial arts actor (d. 1973)
- December 1 - Richard Pryor, actor, comedian
- December 4 - Gary Gilmore, executed killer
- December 5 - Peter Pohl, Swedish writer
- December 12 - Sharad Pawar, Indian politician
- December 21 - Frank Zappa, American rock musician, composer and satirist (d. 1993)
- January 18 - Kazimierz Tetmajer, full name Kazimierz Przerwa-Tetmajer, Polish poet and writer (b. 1865)
- February 11 - John Buchan, 1st Baron Tweedsmuir, Governor General of Canada (b. 1875)
- March 10 - Mikhaïl Boulgakov, Russian writer
- March 16 - Selma Lagerlöf, writer
- May 25 - Joe De Grasse, pioneer Hollywood film director
- May 28 - Friedrich Karl von Hessen (b. 1868)
- June 10 - Marcus Mosiah Garvey, publisher, entrepreneur, black nationalist
- June 29 - Paul Klee, Swiss artist
- July 4 - Robert Pershing Wadlow, tallest man in the world; infection
- August 8 - Johnny Dodds, jazz musician (b. 1892)
- August 21 - Leon Trotsky, Russian revolutionary (b. 1879)
- October 10 - Berton Churchill, pioneer Hollywood actor
- October 11/October 15 - Lluís Companys, President of Catalonia, assassinated (b. 1883)
- November 9 - Neville Chamberlain, Prime Minister of the United Kingdom
- December 5 - Jan Kubelík, violinist