Jean-Ovide Decroly (Ronse, 23 July 1871 – Uccle, 10 September 1932) was a Belgian teacher and psychologist.

He was a freemason, and a member of the lodge Les Amis Philanthropes of the Grand Orient of Belgium in Brussels.

Nowadays the "Ecole Decroly" (based in Uccle, Brussels, a school reaching from kindergarten to baccalaureate) follows his pedagogical approach.

The Decroly plan laid ground rules for social adaptation of a biological organism, in the concrete case, children.

Followers of Decroly have gone on to create and start schools that primarily focus on these "biosocial needs", and better augment the student's educational experience.