Baron Rathcavan

Baron Rathcavan, of The Braid in the County of Antrim, is a title in the Peerage of the United Kingdom. It was created on 11 February 1953 for the Unionist politician Sir Hugh O'Neill, 1st Baronet. He had already been created a baronet, of Cleggan in the County of Antrim, on 17 June 1929 (see O'Neill baronets). O'Neill was the third son of Edward O'Neill, 2nd Baron O'Neill (see the Baron O'Neill for earlier history of the family) and the uncle of the Prime Minister of Northern Ireland Terence O'Neill, Baron O'Neill of the Maine. Lord Rathcavan was also a male-line descendant of Edward Chichester, 1st Viscount Chichester (see the Marquess of Donegall). He was succeeded by his eldest surviving son, the second Baron. He succeeded his father as Unionist Member of Parliament for Antrim in 1952, a seat he held until 1959, and was later a member of the Parliament of Northern Ireland. As of 2025^[update] the titles are held by his grandson, the fourth Baron, who succeeded in 2025.

The Honourable Sir Con O'Neill, second son of the first Baron, was a diplomat. His daughter Onora O'Neill, Baroness O'Neill of Bengarve, is a philosopher.

The family seat is Cleggan Lodge, near Ballymena, County Antrim.^{[citation needed]}

The heir apparent is the present holder's eldest son, the Hon. Tyrone Hugh Richard O'Neill (b. 2023).^{[citation needed]}