Major General Sir Terence O'Brien
Acting Governor of British Ceylon
In office 1 December 1863 – 21 March 1865
Monarch	Queen Victoria
Preceded by	Charles Justin MacCarthy
Succeeded by	Hercules Robinson
22nd General Officer Commanding, Ceylon
In office 1860–?
Preceded by	Henry Frederick Lockyer
Succeeded by	Studholme John Hodson
Personal details
Born	John Terence Nicholls O'Brien 23 April 1830 Manchester, Lancashire, England
Died	25 February 1903(1903-02-25) (aged 72) London, England
Military service
Allegiance	United Kingdom
Branch/service	British Army
Rank	Major general
Commands	General Officer Commanding, Ceylon

Major General Sir John Terence Nicholls O'Brien KCMG (23 April 1830 – 25 February 1903^[1]) was a surveyor, engineer and colonial governor.

Born in Manchester, England, O'Brien studied at Elizabeth College, Guernsey, and then attended the Royal Military College, Sandhurst.

O'Brien, a British Army officer, received a medal of honour for his service in the Indian Mutiny War. He was appointed acting Governor of British Ceylon in 1863 and held the office for two years, succeeding Charles Justin MacCarthy.^[2]

In 1881, he was appointed governor of Heligoland, knighted in 1888 and became governor of Newfoundland in 1889.

O'Brien as governor of Newfoundland helped precipitate the 1894 bank crash by his many dispatches to London noting that Newfoundland politicians under Premier William Whiteway's Liberal Government were uniquely corrupt and incompetent. He resigned from office in 1895 and returned to London.

The Newfoundland community of Terenceville was so named in his honour. O'Brien's son, Sir Charles O'Brien, also became a colonial governor.

O'Brien died in 1903 in London, England.

• Governors of Newfoundland
• List of people from Newfoundland and Labrador

• Biography at Government House The Governorship of Newfoundland and Labrador
• Biography at the Dictionary of Canadian Biography Online