Namesakes
Fictional Characters from Movies:
1 hero
Buck Rogers 1979 Buck Rogers in the 25th Century 
Hall-of-Famers:
3 baseball, 1 football
(baseball) Buck Ewing 1939
(baseball) Buck Leonard 1972
(football) Buck Buchanan 1990
(baseball) Buck O'Neil 2022
Other Fictional Characters:
1 character
Buck Rogers 1929 comic strip