Thomas or Tom O'Neill may refer to:
Thomas O'Neill (Wisconsin politician) (1821–?), member of the Wisconsin State Assembly from Milwaukee Co Thomas J. O'Neill (1849–1919), American merchant Thomas O'Neill (Canadian politician) (1882–1965), Canadian politician, member of parliament for Kamloops Thomas F. O'Neill (1890–1974), American art director Thomas O'Neill (journalist) (1904–1971), American writer for the Baltimore Sun Tip O'Neill (Thomas Phillip O'Neill Jr., 1912–1994), American politician Thomas P. O'Neill (historian) (1921–1996), Irish historian Tom O'Neill (ice hockey) (1923–1973), Canadian ice hockey player Thomas Newman O'Neill Jr. (1928–2018), United States federal judge Thomas P. O'Neill III (born 1945), American politician and leader of a public relations and government affairs firm Tommy O'Neill (born 1955), Scottish footballer
See also Thomas O'Neil (disambiguation) Thomas O'Neal, football coach Tom O'Neill-Thorne (born 1997), Australian wheelchair basketballer Tomás O'Neill, 18th century Spanish colonial governor Thomas Neill (disambiguation)