| William Beckner | |
| Birth Date: | 15 September 1941 |
| Birth Place: | Kirksville, Missouri, US |
| Field: | Mathematics |
| Work Institutions: | University of Texas, Austin Princeton University University of Chicago |
| Alma Mater: | Princeton University University of Missouri (Columbia) |
| Doctoral Advisor: | Elias Stein |
| Doctoral Students: | Emanuel Carneiro |
| Known For: | Sharp Inequalities Babenko–Beckner inequality |
| Awards: | Salem Prize (1975) |
William Beckner (born September 15, 1941) is an American mathematician, known for his work in harmonic analysis, especially geometric inequalities. He is the Paul V. Montgomery Centennial Memorial Professor in Mathematics at The University of Texas at Austin.
Beckner earned his Bachelor of Science in physics from the University of Missouri in Columbia, Missouri in 1963, where he became a member of the Phi Beta Kappa Society. He later earned his Ph.D. in mathematics at Princeton University in Princeton, New Jersey, where his doctoral adviser was Elias Stein. He also completed some postgraduate work in mathematics under adviser A.P. Calderon at the University of Chicago.