Lord O'Neill
Lord O'Neill may refer to:
- Baron O'Neill, a title in the Peerage of the United Kingdom created in 1868
 - Viscount O'Neill, a title in the Peerage of Ireland created in 1795
 - Earl O'Neill, a title in the Peerage of Ireland created in 1800
 - Martin O'Neill, Baron O'Neill of Clackmannan (1945–2020), Scottish politician
 - Jim O'Neill, Baron O'Neill of Gatley (born 1957), British economist
 - Terence O'Neill, Baron O'Neill of the Maine (1914–1990), Prime Minister of Northern Ireland from 1963 to 1969