Timothy O'Sullivan
Timothy O'Sullivan may refer to:
- Timothy H. O'Sullivan, American photographer known for his work on the American Civil War and the Western United States
- Timothy O'Sullivan (Fianna Fáil politician), Irish Fianna Fáil politician, TD for Cork West 1937–1954, Senator 1954–1969
- Timothy O'Sullivan (Irish nationalist politician), Member of Parliament for East Kerry 1910–1918
- Timmy O'Sullivan, Irish Gaelic footballer