Benoît B. Manelbrot (born November 20, 1924) is a Polish-French-Jewish-American mathematician, best known as the "father of fractal geometry". He was born in Poland, but his family moved to France when he was a child; he is a dual French and American citizen and was educated in France. Mandelbrot now lives and works in the United States. He is Sterling Professor of Mathematical Sciences, Emeritus at Yale University; IBM Fellow Emeritus at the Thomas J. Watson Research Center; and Battelle Fellow at the Pacific Northwest National Laboratory.