Jahn (Jähn) is a German surname. Notable people with this surname include the following:
David Jahn (b. 1975), Czech burlesque impresario
Erich Jahn (1907– ?), Hitler Youth leader
Friedrich Ludwig Jahn (1778 – 1852), German educator
Gunnar Jahn (1883 – 1971), Norwegian politician and resistance member
Gunter Jahn (1910 – 1992), German U-boat commander
Helmut Jahn (born 1940), German-American architect
Hermann Arthur Jahn (1907 – 1979), British scientist
Jan Jahn (1739 – 1802), Czech painter and art historian
Jeff Jahn (born 1970), American artist and critic
Johann Jahn (1750 – 1816), German Orientalist
Kurt Jahn (1892 – 1966), German general
Marie-Luise Jahn (1918-2010), German physician
Martin Jahn (born 1970), Czech economist and politician
Joseph Michael Jahn (born 1943), American author and critic
Oliver Jahn, German film director, screenwriter, producer and actor
Otto Jahn (1813 – 1869), German archaeologist, philologist, and writer on art and music
Robert G. Jahn (born 1930), American scientist, electrical engineer, and psychic investigator
Ryan David Jahn (born 1979), American novelist and screenwriter
Sigmund Jähn (born 1937), German astronaut
Thomas Jahn (born 1965), German film and television director
Wilhelm Jahn (1835 – 1900), Austro-Hungarian orchestral conductor
Wilhelm Jahn (athlete) (1889 – 1973), German athlete, leader of the Wandervogel youth movement, folksong composer, publisher, World War II army officer
