A leading scholar in the field of U.S. foreign relations, Paul A. Varg attended Clark University for his bachelor's and master's degrees. He received his PhD from the University of Chicago in 1947 with a dissertation on William Woodville Rockhill, under the influence of Harley F. MacNair.
Varg taught at Ohio State University until 1958, when he moved to Michigan State University. He taught at the Michigan State University from 1958 until his retirement in 1981, and University of Stockholm in 1955–1956 as a visiting Fulbright scholar. From 1962 to 1969, he was the first Dean of the College of Arts and Letters at Michigan State. Varg served as president of the Society for Historians of American Foreign Relations in 1979.