1736- 1801. The son of John Anthony Ommanney and his wife, Elizabeth Page, he was baptised at Portsea, Hampshire, on 15 August 1736.
Ommanney was commissioned lieutenant on 22 August 1758 and promoted commander on 20 June 1765. He commanded the Zephyr 10 from 1766 until the end of the following year, and in February 1768 commissioned the new Otter 14, serving on the Newfoundland station for each of the following two summers and retaining her until the end of 1769.
He was posted captain on 22 February 1772 and commanded the Panther 60 with the broad pennant of Commodore Molyneux Shuldham at Newfoundland for the following two summers.
Ommanney next commanded the Tartar 28 from 1776, going out to North America in the early summer and participating in the campaign to capture New York from July-October. In 1777 he sailed for Quebec with a convoy from New York before returning in July, and thereafter he commanded a squadron of small vessels in the North River. The Tartar was paid off in the autumn of 1778.
He did not see any further service but became a superannuated rear-admiral in 1794 and died on 26 March 1801.
On 19 January 1773 he married Martha Manaton and together they had six sons and a daughter. His sons included Admiral Sir John Acworth Ommanney, Sir Francis Molyneux Ommanney, the M.P. for Barnstaple, Admiral Henry Manaton Ommanney, Captain Cornthwaite Ommanney of the Light Dragoons, and Lieutenant Montagu Ommanney of the Royal Artillery, who died serving in the West Indies in 1796. His address was Millbank Row, Westminster.
Ommanney was regarded by some as a zealous disciplinarian.