Erich Stephen Gruen (/ˈɡruːən/; German: [ˈɡʀuːən]; born May, 1935, in Vienna, Austria) is an American classicist and ancient historian. He was the Gladys Rehard Wood Professor of History and Classics at the University of California, Berkeley, where he taught full-time from 1966 until 2008. He served as president of the American Philological Association in 1992.
Born in Vienna, he received BAs from Columbia University and Oxford University, and the PhD from Harvard University, in 1964. He also received the prestigious Rhodes Scholarship.
His earlier work focussed on the later Roman Republic, and culminated in The Last Generation of the Roman Republic, a work often cited as a response to Ronald Syme's The Roman Revolution. Gruen's argument is that the Republic was not in decay, and so not necessarily in need of "rescue" by Caesar Augustus and the institutions of the Empire. He later worked on the Hellenistic period and on Judaism in the classical world.