Johann Wenzel (born 9 March 1902 in Niedau in Nowy Staw, died 2 February 1969 in Berlin) was a German Communist, agent of the GRU and radio operator of the Red Orchestra in Belgium and the Netherlands.
Wenzel was most notable as the person who exposed the Red Orchestra after his transmissions were discovered by the Funkabwehr, later leading to his captured by the Gestapo on 29–30 June 1942.