He won four Hertzog prizes (in 1947, 1956, 1969 and 1980), four Hofmeyer prizes (in 1954, 1956, 1966 and 1980), two CNA Prizes (in 1964 and 1980), a prize from the "Drie-Eeue Stigting" ("Three Centuries Foundation") in 1956, the Louis Luyt-prize in 1980 and the Gustav Preller prize for literary criticism in 1985.
Hubert Opperman | Dwight D. Opperman | Frank Opperman | Chris Opperman |
In 2002, Forbes 400 ranked Opperman as the 239th richest person in the United States; in 2004, his rank was 315th.
He is a member of the Board of Editors for the Journal of the Kansas Bar Association, the Advisory Board for the Topeka-Shawnee County Youth Court, the United States Supreme Court Historical Society, the Dwight D. Opperman Institute of Judicial Administration at New York University School of Law, the American Judges Association, and the Kansas Bar Association.
Opperman's car was found illegally parked on a street in Vermillion, South Dakota, in the early morning hours of December 10, 1973.