Roger G. Katan is a French-American architect, planner, sculptor, and activist. He was born in Berguent (today's Aïn Bni Mathar), Eastern Morocco. Based in the United States in the early 1960s, Katan became an active founder of advocacy planning, which applies participatory democracy to urban planning. As a kinetic artist, he collaborated and exhibited with rising figures of postmodern art.

After 1975, Katan became involved in humanitarian relief and continued to encourage participatory practices and self-management. His method favors traditional, sustainable agriculture and construction. In 1999, he moved to Sauve, southern France, where he resumed work on kinetic sculpture and publications.