Admiral Sir John Acworth Ommanney KCB (17 October 1773 – 8 July 1855) was a Royal Navy officer who went on to be Commander-in-Chief, Plymouth.

Ommanney joined the Royal Navy in 1786.

[2] Promoted Commander in 1796, he was given command of a brig and arrested a fleet of Swedish merchant ships in the North Sea.

[2] In 1825 he took command of HMS Albion and took part in the Battle of Navarino in 1827.

[2] He was appointed Commander-in-Chief, Lisbon in 1837 and then Second-in-Command of the Mediterranean Fleet in 1840 during the Oriental Crisis.