Erwin Louis Hahn (June 9, 1921 – September 20, 2016) was an American physicist, best known for his work on nuclear magnetic resonance (NMR).

He served as an enlisted sailor in the United States Navy and was an instructor on radar and sonar.

[5] In 2013, Sir Peter Mansfield said in his autobiography that Hahn was "the person who really missed out" the Nobel Prize for his contribution to the principles of spin echoes.

[6] He also received the 2016 Gold Medal from the International Society for Magnetic Resonance in Medicine (ISMRM).

The award, ISMRM's highest honor, was given to Hahn for his creation of pulsed magnetic resonance and processes of signal refocusing which are essential to modern day MRI.