Danny O'Brien
Danny O'Brien may refer to:
- Danny O'Brien (Australian rules footballer), former Australian rules footballer
- Danny O'Brien (boxer), Irish Olympic boxer
- Danny O'Brien (gridiron football), American football quarterback
- Danny O'Brien (journalist), British technology journalist and civil liberties activist
- Danny O'Brien (politician), Australian politician and Member of the Victorian Legislative Council
- Danny O'Brien, character in The Affairs of Martha
- Danny O'Brien (footballer, born 1996), English footballer for Finnish side SJK
- Danny O'Brien (racing driver), 14 time track champion of Brockville Ontario Speedway