Van Cauwelaert was born at Onze-Lieve-Vrouw-Lombeek. He was a member of the Flemish movement, Professor of psychology at the Universite Catholique de Louvain (Leuven), mayor of Antwerp, and co-founder of the journal De Standaard.
He fought for using Dutch at the University of Ghent, together with the Socialist Camille Huysmans and the liberal Louis Franck. In 1911 they proposed a bill to the Belgian parliament, which originated from Lodewijk De Raet for the usage of Flemish at the University of Ghent instead of French. He died at Antwerp.