Pierre Paulus (1881–1959), later Baron Pierre Paulus de Châtelet, was a Belgian expressionist painter. He is best known as the designer of the "bold rooster" adopted on 3 July 1913 as the symbol of the Walloon Movement and today the flag of Wallonia. Paulus gained notability during the Walloon Art Exposition of Charleroi in 1911 and, in the interwar period, he held several exhibitions in Europe and in the United States.