Léopold Leau (1868-1943) was a French mathematician, primarily known for his ties to international auxiliary languages.
The Delegation for the Adoption of an International Auxiliary Language was founded on 7 January 1901 on Leau's initiative.
He co-wrote with Prof.
Louis Couturat the monumental Histoire de la Langue Universelle (1903) and its supplement Les Nouvelles Langues Internationales (1907).