| Last Name Sort descending | First Name | Year | City | Section/Speaker Type |
|---|---|---|---|---|
| Kalai | Gil | 2018 | Rio de Janeiro | Plenary |
| Kàrmàn | Th. V. | 1928 | Bologna | Plenary |
| Kashiwara | M. | 1978 | Helsinki | Plenary |
| Kato | Kazuya | 2006 | Madrid | Plenary |
| Kato | Tosio | 1970 | Nice | Plenary |
| Kazhdan | David | 2022 | Virtual | Plenary Lecture |
| Keisler | H. Jerome | 1970 | Nice | Plenary |
| Keller | Joseph B. | 1994 | Zurich | Plenary |
| Kenig | Carlos | 2010 | Hyderabad | Plenary |
| Kesten | Harry | 2002 | Beijing | Plenary |
| Khot | Subhash | 2014 | Seoul | Plenary/Prize winner |
| Kirwan | Frances Cla | 2002 | Beijing | Plenary |
| Kleene | S. C. | 1958 | Edinburgh | Plenary |
| Klein | F. | 1897 | Zurich | Plenary |
| Kohn | Robert V. | 2006 | Madrid | Plenary |
| Kollár | János | 2014 | Seoul | Plenary |
| Kolmogorov | A. N. | 1954 | Amsterdam | Plenary |
| Kontesevich | Maxim | 1994 | Zurich | Plenary |
| Krasovskii | N. N. | 1978 | Helsinki | Plenary |
| Krein | M. G. | 1966 | Moskva | Plenary |
| Kreiss | Heinz-Otto | 1974 | Vancouver | Plenary |
| Krichever | Igor | 2022 | Virtual | Plenary Lecture |
| Kronheimer | Peter | 2018 | Rio de Janeiro | Plenary |
| Kuznetsov | Alexander | 2022 | Virtual | Plenary Lecture |
| Lafforgue | Laurent | 2002 | Beijing | Plenary/Prize winner |