| Last Name Sort descending | First Name | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Lafforgue | Vincent | 2018 | Rio de Janeiro | Plenary |
| Lamor | Sir J. | 1912 | Cambridge | Plenary |
| Lanczos | C. | 1958 | Edinburgh | Plenary |
| Landau | E. | 1912 | Cambridge | Plenary |
| Langlands | R. P. | 1978 | Helsinki | Plenary |
| Larmor | J. | 1920 | Strasbourg | Plenary |
| Lawler | Gregory | 2018 | Rio de Janeiro | Plenary |
| Lax | P. D. | 1983 | Warszawa | Plenary |
| Le Gall | Jean-François | 2014 | Seoul | Plenary |
| Le Roux | J. | 1924 | Toronto | Plenary |
| Lenstra | H. W. | 1986 | Berkeley | Plenary |
| Lichnerowicz | A. | 1954 | Amsterdam | Plenary |
| Lindenstrauss | Elon | 2010 | Hyderabad | Plenary/Prize winner |
| Lions | J. L. | 1974 | Vancouver | Plenary |
| Lions | Pierre-Louis | 1994 | Zurich | Plenary/Prize winner |
| Lorentz | H.A. | 1908 | Rome | Plenary |
| Lovász | László | 1990 | Kyoto | Plenary |
| Lubich | Christian | 2018 | Rio de Janeiro | Plenary |
| Lubotzky | Alexander | 2018 | Rio de Janeiro | Plenary |
| Lusin | Nicolas | 1928 | Bologna | Plenary |
| Lusztig | George | 1990 | Kyoto | Plenary |
| Lyubich | Mikhail | 2014 | Seoul | Plenary |
| Macdonald | I. G. | 1998 | Berlin | Plenary |
| MacPherson | R. D. | 1983 | Warszawa | Plenary |
| Madsen | Ib | 2006 | Madrid | Plenary |