John Emory Dennis, Jr. (born 1939) is an American mathematician who has made major contributions in mathematical optimization.
Dennis is currently a Noah Harding professor emeritus and research professor in the department of computational and applied mathematics at Rice University in Houston, Texas.
His research interests include optimization in engineering design.
He is the founder and editor-in-chief of the SIAM Journal on Optimization.
[1] In 2010, he was elected a Fellow of the Society for Industrial and Applied Mathematics.