Rear-Admiral Niel O'Neill, R.N. (4 October, 1881 – 12 April, 1953) was an officer in the Royal Navy.
Entered the Navy direct from Worcester.
O'Neill was promoted to the rank of Lieutenant on 31 December, 1903.
O'Neill was promoted to the rank of Lieutenant-Commander on 31 December, 1911.
O'Neill was promoted to the rank of Commander on 31 December, 1914.
O'Neill was promoted to the rank of Captain on 30 June, 1919.
O'Neill was appointed in command of the light cruiser Birmingham on 21 May, 1920.
O'Neill was promoted to the rank of Rear-Admiral on 12 February, 1932 and was placed on the Retired List the following day.