Karel Oliva graduated in Computer Science, with specialization in Computational Linguistics, from the Faculty of Mathematics and Physics of the Charles University in 1983. Between 1983 and 1988, he was a Ph.D. student at the same faculty, however, due to political reasons he was not allowed to defend his Ph.D. thesis (this happened only later, in 1997, at the Faculty of Arts). Because of this, he left Czechoslovakia for Bulgaria illegally in January 1989, and immediately after his arrival to Sofia he started working as a researcher at the Department of mathematical linguistics of the Coordination Centre of Computer Science and Computer Technology of the Bulgarian Academy of Sciences. In October 1989 he legalized his stay abroad, and since April 1990 became a member of the staff of the Institute of Computational Linguistics of the University of Saarland in Saarbrücken (Germany), where he defended his habilitation thesis and was awarded the title of assistant professor („Privatdozent“) in General Linguistics in 2001. Since November of the same year he worked as a senior researcher at the Austrian Research Institute for Artificial Intelligence (OeFAI) in Vienna. Between June 2003 and December 2009 he served as a director of the Institute of the Czech Language ASCR.

His research activities are focussed mainly on formal syntax of natural language, including innovative approaches resulting in commercial applications. He has published over 85 articles in scientific journals and conference proceedings, he was a team leader and co-author of implementations of several software packages (i.a. of a Grammar-checker of Czech for Microsoft Office). He is currently a member of teaching staff of the Faculty of Arts of the Masaryk University in Brno, of the Faculty of Mathematics and Physics of the Charles University in Prague and of the Faculty of Science of the J. E. Purkynie University in Usti nad Labem.

He serves a member of the editorial boards of Slovo a slovesnost („Word and Literature”) and Artificial Intelligence – an International Journal. He is fluent in Bulgarian, English, German, Italian and Russian, and has a partial command of several other languages.