Sir John Macleod Ball (born 19 May 1948) is a British mathematician and former Sedleian Professor of Natural Philosophy at the University of Oxford.

He was the president of the International Mathematical Union from 2003 to 2006 and a Fellow of Queen's College, Oxford.

[2] Ball's research interests include elasticity, the calculus of variations, and infinite-dimensional dynamical systems.

[3] He is a member of the Norwegian Academy of Science and Letters[4] and a fellow of the American Mathematical Society.

In October 2011, he was elected on the executive board of ICSU for a three-year period starting January 2012.