Korovesis was born in Argostoli, Kefalonia, in 1941. He studied theatre with Dimitris Rontiris and Semiotics with Roland Barthes. He also attended some classes of Pierre Vidal-Naquet in Paris. From an early age Korovesis participated actively in the democratic movement. During the military junta (1967–1974) he was arrested, imprisoned and exiled. His first book, The Method: A Personal Account of the Tortures in Greece (Anthropofylakes in Greek), is a personal account of the tortures that he experienced at the police headquarters in Bouboulinas Street at the time of the Colonels' military junta. Korovesis' story was a significant testimony for the Amnesty International and the Council of Europe in order to file charges against the regime of the colonels for the appalling treatment of political prisoners.
Korovesis was an elected Member of Parliament with the left-wing party Coalition of the Radical Left (SY.RIZ.A) in the 2007 Greek legislative election for the Athens A constituency. He failed to be re-elected MP in 2009 elections. He is an advocate of human rights, immigrants, environmental issues and Greek diaspora.
Korovesis has a son.
Korovesis' first book titled Anthropofylakes has been translated into French (Seuil, 1969), English (Alison & Busby, 1970 and Panther,1970), Swedish (Rubén et Sjӧrgen, 1970), Finnish (Weilin+Gӧӧs, 1970), Norwegian (Gyldendal 1973), Turkish (Yӧntem, 1972 & Alan Yayincilik, 1989), German (Zweitausendeins,1981 and Raith,1976), Portuguese (Publicaciōes Europa-America,1970). He has also written poetry and children's stories.
Korovesis has written articles for Eleftherotypia and Epohi newspapers and for the magazine Galera. His personal blog is titled Left Recycling.