Baron Pierre Paulus de Châtelet (16 March 1881 in Châtelet – 17 August 1959 in Brussels) was a Walloon expressionist painter, most known as the designer of "the bold rooster" (French: le coq hardi) adopted on 3 July 1913 by the Walloon Assembly for the flag of Wallonia.
He gained notability during the Wallon Art Exposition of Charleroi in 1911 and, in the interwar period, he held several exhibitions in Europe and in the USA.
- Delforge, Paul; Philippe Destatte; Micheline Libon (2001). Encyclopédie du mouvement wallon — Volume 3 : Lettres O – Z. Charleroi: Institut Jules Destrée. pp. 1244–1245. ISBN 978-2-87035-021-8.