Jacob Cornelius Steyn was born on 31 July 1938 on the farm Mara, in the Fouriesburg district in the Free State. At the end of 1944 his parents moved to the Petrus Steyn district, where he attended a farm school and later the high school in Petrus Steyn.
From 1958 until 1958 he was a full-time student at the University of the Orange Free State and obtained a BA degree with distinctions in the major subjects of Afrikaans-Dutch and German. While working for the Bloemfontein daily Die Volksblad from 1959 until July 1964, he obtained an M.A. in Afrikaans and Dutch (cum laude).
From September 1964 until December 1967 he studied at the Gemeentelijke Universiteit van Amsterdam, where he passed the doctoral examination in 1966 (cum laude), majoring in general linguistics with Dutch linguistics and South Sotho as minor subjects.
From 1968 until June 1970 he lectured in general linguistics at the University of Port Elizabeth, and after that at the Rand Afrikaans University until March 1985. For a short period of time – from July 1974 until August 1975 – he was a member of the senior editorial staff of Rapport. He obtained his doctorate from the University of Port Elizabeth in 1968. From April 1985 until December 1997 he was a professor/researcher at the University of the Free State.
Steyn wrote hundreds of newspaper articles, particularly about language politics, as well as approximately a hundred articles in professional journals and books. He is the author of a volume of poetry, Die grammatika van liefhê (1975), and the following works of fiction: Op pad na die grens (1976), Dagboek van ’n verraaier (1978), Die verlore vader (1985) and Hoeke Boerseuns ons was (1991).
He is also the author of a number of non-fiction books. These are Tuiste in eie taal (1980), Trouwe Afrikaners: Aspekte van Afrikanernasionalisme en Suid-Afrikaanse taalpolitiek 1875-1838 (1987), Van Wyk Louw – ’n lewensverhaal (1998), Penvegter: Piet Cillié van Die Burger (2002) and Die honderd jaar van M.E.R (2004). He is also the author (and in a few cases co-author) of 21 of the 22 articles in W.D Beukes (editor) and J.C. Steyn: Boekewêreld. Die Nasionale Pers in die uitgewersbedryf tot 1990 (1992). With the exception of the last-mentioned book (which was published by Nasionale Boekhandel) all the books were published by Tafelberg.
Steyn received prizes from the Suid-Afrikaanse Akademie vir Wetenskap en Kuns six times. These were the Eugène Marais Prize for debut work for Die grammatika van liefhê (1976), the C.J. Langenhoven Prize for linguistics (1988), the Elisabeth Eybers Bursary for research in the Netherlands (1996), the N.P. van Wyk Louw Medal for creative contributions to the development of certain subject areas (2000), the Stals Prize for history sciences for N.P. van Wyk Louw – ’n lewensverhaal (2003), and the Louis Hiemstra Prize for non-fiction for Die 100 jaar van M.E.R (2005).
Other prizes he has received are the Ingrid Jonker Prize for his poetry debut Die grammatika van liefhê (1976), the Recht Malan Prize for non-fiction twice – for Tuiste in eie taal (1981) and N.P. van Wyk Louw – ’n lewensverhaal (1999), the Louis Luyt Prize for Tuiste in eie taal (1981), and the Insig prize for non-fiction (2000) for N.P. van Wyk Louw – ’n lewensverhaal. In 1993 The Recht Malan Prize for non-fiction was also awarded to the editor and writers of Boekewêreld. Die Nasionale Pers in die uitgewersbedryf tot 1992.