Justice Krzysztof Kolasiński was born on 4 February 1940 in Bydgoszcz. In 1962 he graduated from the Faculty of Law and Administration of Adam Mickiewicz University in Poznań. From 1962 to 1964 he attended judge's training. He earned his juris doctor degree from Adam Mickiewicz University in Poznań in 1965, and a habilitated doctor's degree in 1974. Since 1981 he is a professor of legal sciences and, since 1990, full Professor of Mikołaj Kopernik University [UMK] in Toruń. He served as Director of the Institute of Civil Law of UMK from 1985 to 1990. He is head of the Chair of Labour Law and Social Insurance of UMK.

In 1990 he was appointed judge of the Appellate Court in Gdańsk. From 1991 to 1994 he served as a judge of the Supreme Court.

He is a member of the Polish Section of the International Association of Labour Law and Social Security, a member of Scientific Societies in Toruń and Włocławek.

He is an author of 10 books and above 100 publications in the field of labour law and social insurance.

In May 1994 the Sejm of the Republic of Poland appointed him Justice of the Constitutional Tribunal.