| Last Name Sort descending | First Name | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Majda | Andrew J. | 1990 | Kyoto | Plenary |
| Malgrange | B. | 1966 | Moskva | Plenary |
| Mallat | Stephane | 1998 | Berlin | Plenary |
| Malzev | A. I. | 1966 | Moskva | Plenary |
| Manin | Ju. I. | 1978 | Helsinki | Plenary |
| Marchuk | G. I. | 1970 | Nice | Plenary |
| Marcolongo | Roberto | 1928 | Bologna | Plenary |
| Margulis | Grigorii A. | 1990 | Kyoto | Plenary |
| Marques | Fernando Codá | 2014 | Seoul | Plenary |
| Maslov | V.P. | 1983 | Warszawa | Plenary |
| Maynard | James | 2022 | Virtual | Plenary/Prize winner |
| Mazur | B. | 1983 | Warszawa | Plenary |
| McDuff | Dusa | 1998 | Berlin | Plenary |
| Melrose | Richard B. | 1990 | Kyoto | Plenary |
| Menger | Karl | 1932 | Zurich | Plenary |
| Merle | Frank | 2014 | Seoul | Plenary |
| Milner | E. C. | 1974 | Vancouver | Plenary |
| Milnor | J. | 1962 | Stockholm | Plenary/Prize winner |
| Mirzakhani | Maryam | 2014 | Seoul | Plenary (lecture was not given)/Prize winner |
| Mittag-Leffler | G. | 1900 | Paris | Plenary |
| Mittag-Leffler | G. | 1908 | Rome | Plenary |
| Miwa | Tetsuji | 1998 | Berlin | Plenary |
| Mochizuki | Takuro | 2014 | Seoul | Plenary |
| Mordell | L. J. | 1936 | Oslo | Plenary |
| Moreira | Carlos Gustavo | 2018 | Rio de Janeiro | Plenary |