Alan G. Marshall is an American analytical chemist who has devoted his scientific career to developing a scientific technique known as Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry, which he co-invented. He was born in Bluffton, Ohio, in 1944, and earned his Bachelor's in Chemistry from Northwestern University (1965) and Ph.D. in Chemistry from Stanford University (1970). His first academic appointment was at the University of British Columbia. In 1980, he moved to the Ohio State University where he remained until 1993.