Juan Bautista Justo (born June 28, 1865 in Buenos Aires – died on January 8, 1928 in Buenos Aires) was an Argentine physician, journalist, politician, and writer.
After finishing medical school he joined the Unión CÃvica Radical, later participating in the foundation of the Socialist Party in 1896, of which he was chief director until his death.
He married Alicia Moreau de Justo, with whom he had three children.