In 1951, he received his doctoral degree in philology from Harvard University for his dissertation Cicero's Concept of Historiography.

Feldman was a co-recipient of the 2014 National Jewish Book Award in the Scholarship category for editing Outside the Bible with James L. Kugel and Lawrence H.

[3] As a historian, Feldman dealt primarily with the writings of Josephus and their role within the larger framework of Jewish civilization during the Second Temple Period.

Overall, he viewed Josephus' work as key to understanding Jewish life and interactions with Hellenistic culture during the Greco-Roman era.

He served as departmental editor of Hellenistic literature for the first edition of Encyclopedia Judaica and as a contributor to the Encyclopædia Britannica.