Johannes Hendrik Voskuijl (15 January 1892 – 27 November 1945) was one of the people who helped to hide Anne Frank and the other people of the Secret Annex in Amsterdam. In the earliest editions of Het Achterhuis, known in English as The Diary of Anne Frank, Voskuijl is referred to as "Mr. Vossen", as he was the father of helper Bep Voskuijl, who is named "Elli Vossen" in the diary. Voskuijl built the famous bookcase that covered the hiding place.