| Last Name Sort descending | First Name | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Siu | Yum-Tong | 2002 | Beijing | Plenary |
| Skorokhod | A. V. | 1986 | Berkeley | Plenary |
| Smale | S. | 1966 | Moskva | Plenary/Prize winner |
| Smale | S. | 1986 | Berkeley | Plenary |
| Smirnov | Stanislav | 2010 | Hyderabad | Plenary/Prize winner |
| Soundararajan | Kannan | 2022 | Virtual | Plenary Lecture |
| Spielman | Daniel A. | 2010 | Hyderabad | Plenary/Prize winner |
| Stanley | Richard P. | 2006 | Madrid | Plenary |
| Steenrod | N. E. | 1958 | Edinburgh | Plenary |
| Stein | Ch. M. | 1966 | Moskva | Plenary |
| Stein | E. M. | 1970 | Nice | Plenary |
| Stein | E. M. | 1986 | Berkeley | Plenary |
| Stenzel | J. | 1932 | Zurich | Plenary |
| Stiefel | E. | 1954 | Amsterdam | Plenary |
| Störmer | C. | 1908 | Rome | Plenary |
| Stroppel | Catharina | 2022 | Virtual | Plenary Lecture |
| Størmer | C. | 1924 | Toronto | Plenary |
| Størmer | Carl | 1936 | Oslo | Plenary |
| Sudan | Madhu | 2002 | Beijing | Plenary/Prize winner |
| Sullivan | D. | 1974 | Vancouver | Plenary |
| Suslin | A. A. | 1986 | Berkeley | Plenary |
| Swan | Richard G. | 1970 | Nice | Plenary |
| Talagrand | Michel | 1998 | Berlin | Plenary |
| Tao | Terence | 2006 | Madrid | Plenary/Prize winner |
| Tarski | A. | 1954 | Amsterdam | Plenary |