Shmuel Noah Eisenstadt (Hebrew: שמואל נח אייזנשטדט) (September 10, 1923 – September 2, 2010) was an Israeli sociologist. In 1959 he was appointed to a teaching post in the sociology department of the Hebrew University in Jerusalem. From 1990 until his death in September of 2010 he had been a professor emeritus. He held countless guest professorships, at among others, the University of Chicago, Harvard University, the University of Zurich, the University of Vienna, the University of Bern, Stanford and the University of Heidelberg. Eisenstadt received a number of prizes, the Balzan prize and the Max-Planck research prize. He was also the 2006 winner of the Holberg International Memorial Prize. He was a member of many academies, including the American Academy of Arts and Sciences and the Advisory Editors Council of the Social Evolution & History Journal.

In the field of sociology he became known as a "sociologist of youth" ( after a term in From Generation to Generation a work closely related to the ideas of Talcott Parsons.