Born in St Helier, Jersey, Ouless attended the Royal Academy Schools from the age of 16. He first exhibited at the Royal Academy at 20 and in 1881 he was elected as an academician. He became a senior academician in 1924. He concentrated on portraiture from early in his career on the advice of Sir J. E. Millais. Some of his key works include portraits of Charles Darwin, Thomas Hardy, Cardinal Newman, Edward VIII and George V. He died in London in 1933.