Koll was born on 19 March 1958 in Bensberg, Bergisch Gladbach, North Rhine-Westphalia, Germany.

[1] From 1977 to 1985, he studied political science, modern history, sociology and constitutional law at the University of Bonn, as well as in London, Paris and Hamburg with a master's degree.

[2] In addition, he presented the theater magazine Foyer on 3sat from October 2006 to April 2010, alternating with Esther Schweins.

[4] In 2016, was one of the final candidates considered for the leadership of public broadcaster RBB; the position eventually went to Patricia Schlesinger instead.

[2] On 1 March 2019, he took over the management of the ZDF capital studio in Berlin, succeeding Bettina Schausten.