Academic painter, graphic artist, illustrator, lecturer. Karol Ondreička studied on the Faculty of Education in Nitra (1962–1966), and later continued his studies at the Department of Illustration and Book Production of the Academy of Fine Arts and Design in Bratislava (1968–1974) under the guidance of Prof. Albín Brunovský. In 1984, he participated in an educational exchange programme at the Loughborough University, School of Art and Design, East Midlands, UK. Five years later, he became a senior lecturer, and in 1991 was appointed as a professor. For thirteen years, Karol Ondreička worked at the Department of Illustration and Book Production of the Academy of Fine Arts and Design, and from 1989 to 1990 acted as a rector of the school. After leaving the Academy of Fine Arts and Design, he taught drawing and graphic arts on the J. A. Komenský University Faculty of Education in Bratislava, greatly contributing to the formation of the Department of Fine Arts there. Karol Ondreička was a co-founder of the G-BOD Association of graphic artists.