Alfred Jonniaux (22 November 1882—1974) was a Belgian portrait painter who worked in London and the United States of America.
He worked in Paris and established a successful career as a portraitist in London, with a studio in Yeoman's Row, Chelsea.
He painted the portraits of society figures, and members of the European aristocracy and royal families.
Following the Nazi occupation of Belgium during World War II, he fled to the United States of America, and became an American citizen in 1946.
During his first ten years in America, he established studios in San Francisco and Washington, D.C. His exhibitions led to many portrait commissions from leading figures in all spheres of American life.