- Fischer, Hans Fischer - German chemist noted for his synthesis of hemin (1881-1945)
--1 is a kind of chemist
- Fischer, Emil Hermann Fischer - German chemist noted for work on synthetic sugars and the purines (1852-1919)
--2 is a kind of chemist
- Fischer, Bobby Fischer, Robert James Fischer - United States chess master; world champion from 1972 to 1975 (born in 1943)
--3 is a kind of chess master