Mark Buchanan (born October 31, 1961, in Cleveland, Ohio) is an American outreach physicist and author.
He has been a guest columnist for the New York Times, and currently writes a monthly column for the journal Nature Physics.
Key themes include, but are not limited to the (often overlooked) importance of spontaneous order or self-organization in collective, complex systems.
All of his work aims to bring technical advances in modern science to a broad, non-technical audience, and to help stimulate the flow of ideas across disciplinary boundaries.
He has been awarded, in June 2009, the Lagrange Prize in Turin, regarding science writing in the field of complexity.