He was born in Donje Jesenje. He received a degree in Romance and Russian philology at the Faculty of Philosophy in Zagreb in 1960, and a PhD in 1965. In the period 1960-62 he worked as Croatian language editor at the University of Bucharest. In 1962 he started working at the Department of Romance Languages at the Faculty of Philosophy in Zagreb, becoming professor in 1983. During the 1966-1967 he went to Paris to further study under André Martinet and Émile Benveniste.
His work is focused on the Istro-Romanian language (Opis današnjeg istrorumunjskog – Descrierea istroromânei actuale, 1971; Istrorumunjsko-hrvatski rječnik: (s gramatikom i tekstovima), 1998) as well as Jewish-Spanish spoken in Dubrovnik and Sarajevo and their contacts with Croatian. He published papers on French language, Romance comparative syntax, on Balkans languages and Romance literatures (Francuska književnost XIV. do XVI. st., Rumunjska književnost, in: Povijest svjetske književnosti, book 3, 1982). At the Miroslav Krleža Lexicographical Institute he was the Editor-in-Chief of the Croatian General Lexicon (1991-1996), then deputy editor (1996-2001) and finally the Editor-in-Chief of Croatian Encyclopedia (2001–05). His articles on Croatian language policy meet criticism, arising from Kovačec's puristic approach to language and the primordialist view of nations.
- "Kovačec, August", Croatian Encyclopedia (in Serbo-Croatian), Leksikografski zavod Miroslav Krleža, 1999–2009, retrieved January 2, 2014
- Kordić, Snježana (2008). "O naciji, povijesti i jeziku (odgovor Augustu Kovačecu)" [About nation, history, and language (response to August Kovačec)] (PDF). Književna republika (in Serbo-Croatian). Zagreb. 6 (1-2): 186–208. ISSN 1334-1057. OCLC 70236267. ZDB-ID 2122129-7. Archived from the original (PDF) on 3 March 2014. Retrieved 8 May 2015. (NSK).
- "SOS ili tek alibi za nasilje nad jezikom" [SOS or nothing but an alibi for violence against language] (in Serbo-Croatian) (27). Zagreb: Forum. 16 March 2012. pp. 38–39. ISSN 1848-204X. Archived from the original on 7 July 2012. Retrieved 2 August 2013.