Pierre Auguste Brahain Ducange (Tours, ? — Paris, 1833) was a French journalist, minor diplomat, secret agent, swindler, and author. He was the father of the French author Victor Henri Joseph Brahain Ducange. He played an important role in the coup d'état of 22 January 1798 in the Batavian Republic, by general Herman Willem Daendels, which brought the radical unitarist faction of Wybo Fijnje and Pieter Vreede to power, and he helped write the Staatsregeling voor het Bataafse Volk of 1798 (the first Dutch Constitution).