1909

1909 (MCMIX) was a common year starting on Friday in the Gregorian calendar and a common year starting on Thursday in the Julian calendar.

 Events 
 March 31 – Construction of the RMS Titanic is started
 April 6 – Robert Peary arrived in the north pole.
 April – The Adana massacre takes place in the Ottoman city of Adana
 June 29 – Alfred Deakin becomes Prime Minister of Australia
 The first model of the Model T is sold
 The pH scale is developed.
 Emil Theodor Kocher, Swiss doctor, won the 1909 Nobel Prize in Physiology or Medicine

 Births 
 January 13 – Danny Barker, American musician (d. 1994)
 February 9 – Carmen Miranda, Brazilian singer and actress (d. 1955)
 March 20 – Juliana of the Netherlands (d. 2004)
 May 27
 Dolores Hope, American singer (d. 2011)
 Juan Vicente Pérez, Supercentenarian Venezuelan man fourth-oldest verified man ever (d. 2024)
 June 6 – Isaiah Berlin, Latvian philosopher and educator (d. 1997)
 June 10 – Errol Flynn, American actor (d. 1959)
 August 10 – Leo Fender, American guitar maker (d. 1991)
 August 21  Ethel Caterham, British supercentenarian
 August 26 – Sylvère Maes, Belgian cyclist (d. 1966)
 September 21 – Kwame Nkrumah, President of Ghana (d. 1972)

 Deaths 
 February 17 – Geronimo, Native American leader (b. 1829)
 December 17 – Léopold II of Belgium, King of Belgium (b. 1835)
 January 12 – Hermann Minkowski, German mathematician (b. 1864)