Cornelis Gerrit "Kees" van der Staaij is a Dutch former politician who served as a member of the House of Representatives from 1998 to 2023 and Leader of the Reformed Political Party between 2010 and 2023. As a parliamentarian, he focused on matters of judiciary, home affairs, Kingdom relations, foreign policy, the European Union, development aid, the defense, public health, welfare, sports, immigration and political asylum. Van der Staaij was the longest-serving member of the House of Representatives from 2017 until 2023.