Kees de Boer was born in Hoorn, The Netherlands. He studied at the Graphic Art school in Amsterdam for four years. He made his debut in underground magazines like Crash and Coyote, and with a regular cartoon in Noord-Hollands Dagblad in alternation with Coyote-colleague Barend Lammes. He first worked for Oberon/VNU when he succeeded Wilbert Plijnaar as the illustrator of the questions section in Mickey Maandblad. De Boer is still working for the Dutch Disney magazines to this day; he is the regular illustrator of the jokes section in the weekly magazine Donald Duck.
Hoofdpijn, reumatiek (Coyote #6, May 1984)
He had his breakthrough as a comic artist in 1987, when he joined the team of Eppo/Wordt Vervolgd. For this magazine, he made the comic 'Max Laadvermogen' with writer Jan Schrijver, of which one album has been published. Together with writer Rolf Hartog van Banda, he created the serial 'Sidi en Smook' for Donald Duck in 1992.
Kees de Boer had joined Aloys Oosterwijk, Ben Jansen, René Meulenbroek, Hanco Kolk and Gerard Leever in their Studio Arnhem around 1987. In the late 1980s, he started his own with Frans Leenheer and Stef de Reuver. Funny Farm, that is also based in Arnhem, remains an inspirational environment for Dutch comic artists, illustrators and other creatives to this day. Many artists have frequented the studio, such as Gerard Leever, Marja Meijer, Mars Gremmen, Mark Retera, Hendrik J. Vos, Hester van der Grift, Yvonne Jagtenberg, Roel Venderbosch, Tom Jilesen, Maarten Gerritsen, Jordi Peters, Michiel van de Vijver, Hanco Kolk, Jeroen Steehouwer, Jaap Stavenuiter, Leo de Winter, Emma Ringelding and Abe Borst. In the 1990s, she studio was also responsible for the comics magazine Razzafrazz.
De Boer has worked with Gerard Leever in both Studio Arnhem and Studio Funny Farm. They cooperated on the scenarios of the series 'Felix Flux Museum' for Sjors en Sjimmie Stripblad, as well as 'Junior Reporter' for Junior, both with art by Gleever. De Boer has also done illustration work for Panorama, Wolters Noordhoff, EPN and almost every children's magazine published by Malmberg and Sanoma. His comic 'Gustaaf Raaf' was published in Taptoe.
De Boer has been mainly active as a children's book illustrator since 1996. He has worked extensively with Tjibbe Veldkamp on several books, including the 'Agent en Boef' series. In 2014 he hosted the online interview series 'Stripmakers drinken wijn aan het water' in commission of the Dutch Association of Comic Authors.