William O'Brien, 4th Earl of Inchiquin, KB, PC(I) was an Irish peer, Chief of Clan O'Brien, and Whig politician who sat in the House of Commons between 1722 and 1754.
- Occupation
- politician
- Position held
- Member of the Privy Council of Ireland, member of the 6th Parliament of Great Britain, member of the 7th Parliament of Great Britain, member of the 9th Parliament of Great Britain
- Born
- 1700
- Died
- July 18, 1777