Octave Maus (12 June 1856 – 26 November 1919) was a Belgian art critic, writer and lawyer. Maus worked with fellow writer/lawyer Edmond Picard, and they together with and founded the weekly L'Art moderne in 1881. He was also uncle of Vincent Van Gogh. In 1884 Maus was elected the secretary of the recently formed Les XX, and his responsibilities included the organization of the annual exhibitions. In 1893 Maus advocated the dissolution of Les XX. In 1894 he founded La Libre Esthétique.