1909

• January 5 - Colombia recognizes the independence of Panama.
• January 16 - Ernest Shackleton's expedition finds the magnetic South Pole.
• January 28 - United States troops leave Cuba after being there since the Spanish-American War.
• February 12 - The National Association for the Advancement of Colored People (NAACP) is founded.
• February 23 - The Silver Dart makes the first powered flight in Canada and the British Empire.
• February 24 - The Hudson Motor Car Company is founded.
• March 18 - Einar Dessau uses a short-wave radio transmitter becoming the first to broadcast as a ham radio operator.
• March 23 - Theodore Roosevelt leaves New York for a post-presidency safari in Africa. The trip was sponsored by the Smithsonian Institution and National Geographic Society.
• March 31 - Serbia accepts Austrian control over Bosnia-Herzegovina.
• April 6 - Robert Peary allegedly reaches the North Pole.
• April 27 - Sultan of Turkey Abdul Hamid II is overthrown, and is succeeded by his brother, Murat V.
• June 1 - The Alaska-Yukon-Pacific Exposition opens in Seattle.
• July 13 - Gold discovered near Cochrane, Ontario.
• July 25 - Louis Bleriot is the first man to fly across the English Channel in a heavier-than-air craft.
• September 9 - Comet Halley first recorded on a photographic plate.
• November 13 - Ballinger-Pinchot scandal begins: Collier's magazine accuses US Secretary of the Interior Richard Ballinger of questionable dealings in Alaskan coal fields.
• November 18 - Two United States warships are sent to Nicaragua after 500 revolutionaries (including two Americans) are executed by order of dictator Jose Santos Zelaya.
• Change of US president from Theodore Roosevelt (1901-1909) to William Howard Taft (1909-1913).
• Albert I of Belgium succeeds Leopold II.
• The Boy Scouts of America is founded.
• Construction begins on the Cape Cod Canal.
• Karl Landsteiner develops system of blood groups.
• Leon's, a Canadian furniture chain is first opened.
• Britain introduces Minimum Wage Laws.

• 1909 in aviation
• Sophie Tucker first appears in the Ziegfeld Follies.
• 1909 in film
  • Thomas Edison formed the Motion Picture Patents Company.
  • Mary Pickford first appears in a film (The Lonely Villa).
• 1909 in literature
• 1909 in music
• 1909 in science
• 1909 in sports

• January 1 - Barry Goldwater, American politician (d. 1998)
• January 3 - Victor Borge, Danish entertainer (d. 2000)
• January 5 - Stephen Cole Kleene, American mathematician (d. 1994)
• January 8 - Willy Millowitsch, actor (d. 1999)
• January 15 - Gene Krupa, drummer (d. 1973)
• January 16 - Ethel Merman, singer, actress (d. 1984)
• January 22 - U Thant, 3rd United Nations Secretary General (d. 1974)
• January 22 - Ann Sothern, actress (d. 2001)
• February 3 - Simone Weil, philosopher (d. 1943)
• February 9 - Dean Rusk, United States Secretary of State (d. 1994)
• February 9 - Carmen Miranda, actress, singer (d. 1955)
• February 11 - Joseph Mankiewicz, filmmaker (d. 1993)
• February 11 - Max Baer (The Livermore Larruper), American boxer/actor (d. 1959)
• February 15 - Guillermo Gorostiza Paredes, Spanish football player (d. 1966)
• February 15 - Miep Gies (Hermine Santrouschitz), Anne Frank friend, biographer
• February 24 - August Derleth, American writer (d. 1971)
• February 26 - King Talal, King of Jordan (d.1972)
• March 1 - David Niven, actor (d. 1983)
• March 2 - Mel Ott, Baseball Hall of Famer
• March 4 - Harry Helmsley, real estate entrepreneur (d. 1997)
• March 19 - Louis Hayward, actor (d. 1985)
• March 22 - Gabrielle Roy, author (d. 1983)
• March 24 - Clyde Barrow, half of American criminal duo (d. 1934)
• March 27 - Golo Mann, historian and publicist (d. 1994)
• April 13 - Stanislaw Marcin Ulam, Polish/American mathematician (d. 1984)
• April 30 - Juliana of the Netherlands
• May 7 - Edwin H. Land, inventor and founder of Polaroid (d. 1991)
• May 10 - Mother Maybelle Carter, country musician
• May 15 - James Mason, British actor (d. 1984)
• May 19 - Bruce Bennett, actor
• May 30 - Benny Goodman, American jazz musician (d. 1986)
• June 17 - Elmer Lee Andersen, governor of Minnesota
• June 20 - Errol Flynn, Australian actor (d. 1959)
• July 18 - Mohammed Daoud Khan, Afghan president (d. 1978)
• July 28 - Malcolm Lowry, British novelist (d. 1957)
• July 30 - C. Northcote Parkinson, British historian and author (d. 1993)
• August 9 - Adam von Trott zu Solz, lawyer, diplomat (d. 1944)
• August 25 - Ruby Keeler, singer, actress (d. 1993)
• August 26 - Jim Davis, actor (d. 1981)
• September 14 - Peter Scott, British ornithologist and painter (d. 1989)
• September 21 - Kwame Nkrumah, Ghanian politician (d. 1972)
• September 28 - Al Capp, American cartoonist (d. 1979)
• October 28 - Francis Bacon, British painter (d. 1992)
• November 4 - Skeeter Webb, Professional Baseball Player (d. 1986)
• November 10 - Paweł Jasienica, Polish historian (d. 1970)
• November 18 - Johnny Mercer, American songwriter (d. 1976)
• November 24 - Gerhard Gentzen, German mathematician (d. 1945)
• December 23 - Barney Ross, American boxing champion (d. 1967)
• Giulio Racah, Italian mathematician and physicist (d. 1965)

• January 12 - Hermann Minkowski, German mathematician
• January 14 - Arthur William a Beckett, British journalist
• April 12 - Algernon Charles Swinburne, British poet
• May 19 - Isaac Albéniz, Spanish composer
• August 27 - Emil Christian Hansen, Danish fermentation physiologist
• December 17 - Leopold II of Belgium

• Physics - Guglielmo Marconi, Carl Ferdinand Braun
• Chemistry - Wilhelm Ostwald
• Medicine - Emil Theodor Kocher
• Literature - Selma Lagerlöf
• Peace - Auguste Marie Francois Beernaert and Paul Henribenjamin Balluet D'estournelles De Constant, Baron De Constant De Rebecque

• China - Xuantong Emperor of China, Qing Dynasty (1908-1912)
• Denmark - Frederick VIII, King of Denmark (1906-1912)
• France - Armand Fallières, President of France (1906-1913)
• Germany - Wilhelm II, German Kaiser (1888-1918)
• Holy See - Pope Pius X, Bishop of Rome (1903-1914)
• Japan - Mutsuhito, Meiji Emperor (1867-1912)
• Norway - Haakon VII, King of Norway (1905-1957)
• Ottoman Empire -
• Abdul Hamid II, Sultan of the Ottoman Empire (1876-1909)
• Mehmed V, Sultan of the Ottoman Empire (1909-1918)
• Russia - Nicholas II, Tsar of Russia (1894-1917)
• Spain - Alfonso XIII of Spain, King of Spain (1886-1931)
• United States -
• Theodore Roosevelt, President of the United States (1901-1909)
• William Howard Taft, President of the United States (1909-1913)