Peter O'Brien
Peter O'Brien may refer to:
- Peter O'Brien (actor), Australian actor
- Peter O'Brien, 1st Baron O'Brien
- Peter O'Brien (filmmaker)
- Peter O'Brien (politician)
- Peter O'Brien (catcher) (born 1990), Minor League Baseball player
- Pete O'Brien (first baseman) (born 1958), MLB first baseman, 1982–1993
- Pete O'Brien (1900s second baseman) (1877–1917), MLB second baseman, 1901–1907
- Pete O'Brien (1890s second baseman) (1867–1937), MLB second baseman, 1887–1890
See also
- Peter O'Brian (disambiguation)