| Last Name Sort descending | First Name | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Mori | Shigefumi | 1990 | Kyoto | Plenary/Prize winner |
| Morse | M. | 1950 | Cambridge (USA) | Plenary |
| Morse | Marston | 1932 | Zurich | Plenary |
| Moser | Jürgen | 1998 | Berlin | Plenary |
| Mrowka | Tomasz | 2018 | Rio de Janeiro | Plenary |
| Mumford | David | 2002 | Beijing | Plenary |
| Nakajima | Hiraku | 2002 | Beijing | Plenary |
| Naor | Assaf | 2018 | Rio de Janeiro | Plenary |
| Nemivroski | Arkadi | 2006 | Madrid | Plenary |
| Neugebauer | O. | 1936 | Oslo | Plenary |
| Nevanlinna | Rolf | 1932 | Zurich | Plenary |
| Newcomb | S. | 1908 | Rome | Plenary |
| Newman | M. H. A. | 1962 | Stockholm | Plenary |
| Neyman | J. | 1954 | Amsterdam | Plenary |
| Ngo | Bao Chau | 2010 | Hyderabad | Plenary/Prize winner |
| Nielsen | Jakob | 1936 | Oslo | Plenary |
| Nikolskii | S. M. | 1954 | Amsterdam | Plenary |
| Nirenberg | L. | 1962 | Stockholm | Plenary |
| Noether | Emmy | 1932 | Zurich | Plenary |
| Noether | M. | 1908 | Rome | Plenary |
| Nörlund | N.E. | 1920 | Strasbourg | Plenary |
| Novikov | S. P. | 1978 | Helsinki | Plenary |
| Okounkov | Andrei | 2018 | Rio de Janeiro | Plenary |
| Ore | Øystein | 1936 | Oslo | Plenary |
| Oseen | C. W. | 1936 | Oslo | Plenary |