| Last Name | First Name Sort descending | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Perron | O. | 1928 | Bologna | Analysis |
| Spiess | O. | 1936 | Oslo | Logic, Philosophy, and History |
| Szász | O. | 1928 | Bologna | Analysis |
| Taussky | O. | 1936 | Oslo | Algebra and Number Theory |
| Tedone | O. | 1908 | Rome | Mechanics, Physical Mathematics, Astronomy |
| Volk | O. | 1928 | Bologna | Geometry |
| Zariski | O. | 1928 | Bologna | Geometry |
| Zariski | O. | 1950 | Cambridge (USA) | Algebraic Geometry |
| Zeitouni | O. | 2002 | Beijing | Prob & Stats |
| Ladyzenskaja | O. A. | 1966 | Moskva | Applied mathematics & mathematical physics |
| Oleinik | O. A. | 1970 | Nice | Analysis |
| Smith | O. A. | 1928 | Bologna | Analysis |
| Hazlett | O. C. | 1928 | Bologna | Analysis |
| Glenn | O. E. | 1928 | Bologna | Analysis |
| Lanford | O. E. | 1986 | Berkeley | Numerical Methods & Computing |
| Bogoyavlensky | O. I. | 1978 | Helsinki | Geometry |
| Besov | O. V. | 1970 | Nice | Analysis |
| Viro | O. Ya. | 1983 | Warszawa | Geometry |
| Hazlett | O.C. | 1924 | Toronto | Algebra, Theory of Numbers, Analysis |
| Glenn | O.E. | 1924 | Toronto | Algebra, Theory of Numbers, Analysis |
| Oniecescu | Octav | 1936 | Oslo | Probability Calculus, Mathematical Statistics, Insurance Mathematics, and Econometry |
| Goldreich | Oded | 1994 | Zurich | Mathematical Aspects of Computer Science |
| Schramm | Oded | 2006 | Madrid | Plenary |
| Regev | Oded | 2022 | Virtual | Mathematics of Computer Science |
| Devisme | Odette | 1932 | Zurich | Analysis |