Kåre Dorenfeldt Tønnesson (born 1 January 1926) is a Norwegian historian.
He was born in Ski, and grew up in Bærum. He has resided at Ringstabekk and Hamang. He is the father of Stein Tønnesson.
He finished his secondary education at Valler in 1944, and after enrolling in philological studies at the University of Oslo in 1945 he graduated with the cand.philol. degree in history in 1952. His master's thesis delved into causality in the writings of . In 1959 Tønnesson took the dr.philos. degree with the thesis La défaite des sans-culottes, "The Defeat of the Sans-culottes".
He was a lecturer in history at the University of Oslo from 1958, research fellow from 1960, docent from 1964 and professor from 1969 to 1991. From 1973 to 1975 he was the dean at the Faculty of History and Philosophy. After retiring from the professorship, he was a scholar in NAVF and the Research Council of Norway. Larger works include volume four of Sentraladministrasjonens historie in 1979 and volume ten of Aschehougs verdenshistorie in 1985. This was also translated to Swedish and also reissued in 2001. In 1989 he marked the 200th anniversary of the French Revolution with the book Revolusjonen som rystet Europa. This too was translated into Swedish. In 2007 he released a biography on Madame de Staël.
A Festschrift in Tønnesson's honor was released in 1995, and he is a fellow of the Norwegian Academy of Science and Letters.