Tim or Timothy O'Brien may refer to:
Arts and entertainment Tim O'Brien (record producer), American record producer and music industry executive. Tim O'Brien (author) (born 1946), American novelist Tim O'Brien (illustrator) (born 1964), American artist Tim O'Brien (musician) (born 1954), American country and bluegrass singer Timothy O'Brien (theatre designer) (1929–2022), British theatre designer
Sports Sir Tim O'Brien, 3rd Baronet (1861–1948), Irish-born cricketer Tim O'Brien (footballer) (born 1994), Australian rules footballer Tim O'Brien (rugby union), head coach of St. Mary's Gaels rugby
Other Sir Timothy O'Brien, 1st Baronet (1787–1862), Irish politician and merchant Tim O'Brien (physicist) (born 1963), astrophysicist at the University of Manchester Tim O'Brien (Connecticut politician) (born 1968), legislator in the Connecticut House of Representatives Tim O'Brien (Indiana politician), member of the Indiana House of Representatives Timothy O'Brien (endocrinologist), Irish professor Timothy L. O'Brien (born 1961), American journalist
See also Timothy (given name) O'Brien (disambiguation)