István Hajnal (3 July 1892 – 16 June 1956) was a Hungarian social historian and palaeographer. Hajnal has been characterised as "perhaps the most prominent Hungarian palaeographer of [the twentieth] century." He had wide-ranging interests in medieval and modern history, including the history of technology, the history of communication, and the relation of history to sociology.
Hajnal was born in Nagykikinda, in the Kingdom of Hungary. In 1921 he gained his Privatdocent, and started teaching at the University of Budapest, where he was Professor of Modern History from 1930 to 1949. He became a corresponding member of the Hungarian Academy of Sciences in 1928, and was an Academician from 1939 to 1949. He was also an official at the Hungarian National Museum.
In the 1980s Hajnal's work, promoted by László Lakatos, "suddenly burst into public consciousness as an oeuvre comparable with and compatible with the Annales. The István Hajnal Circle [Hajnal István Kör], named after him, sponsors research into East Central European social history.
- L'enseignement de l'écriture aux universités médiévales, 1959.
- Az újkor története [History of the Modern Age], Budapest: Akadémiai Kiadó, 1988.
- László Veszpremy (2002). "On the margins of book and charter palaeography, the dating of some Hungarian manuscripts from the eleventh to the thirteenth century". In Michael Gervers. Dating Undated Medieval Charters. Boydell & Brewer Ltd. p. 193. ISBN 978-0-85115-924-9. Retrieved 14 February 2013.
- 'Hajnal, István', The Great Soviet Encyclopedia, 3rd ed., Gale Group, 1970-1979. Reprinted online here
- Dirk Kasler; Stephen Turner, ed. (14 January 2004). Sociology Responds to Fascism. Routledge. p. 162. ISBN 978-0-203-16907-0. Retrieved 16 February 2013.
- László Lakatos, 'Az elfelejtett Hajnal István. Az iráskultúra és a kapitalizmus szelleme: Hajnal István 1933/34-es tanulmányai' [The forgotten István Hajnal. Culture of writing and the spirit of capitalism: István Hajnal's studied from 1933/34], Medvetánc, Vol. 2-3 (1982), pp.305-19.
- Review of János Bak, ed., History and Society in Central Europe.