George Spencer Watson was an English portrait artist of the late romantic school who sometimes worked in the style of the Italian Renaissance.

He studied at the Royal Academy Schools from 1889, and exhibited at the Royal Academy from 1891. He won Royal Academy Schools Silver Medals in 1889 and 1891, and the Landseer Scholarship in 1892. He was elected to the Royal Institute of Oil Painters (ROI) in 1900, Royal Society of Portrait Painters (RP) in 1904, Associate of the Royal Academy in 1923, and a Member of the Royal Academy (RA) in 1932. His work was also part of the painting event in the art competition at the 1928 Summer Olympics.

In 1909 he married Hilda Mary Gardiner, a dancer and mime artist, and follower of the actor Edward Gordon Craig. They had a daughter, Mary Spencer Watson (1913–2006), who became a sculptor. In the year of 1923 he bought Dunshay Manor in the hills of the Isle of Purbeck, after already having spent holidays in nearby Swanage.

He died in London and a memorial exhibition was held at the Fine Art Society in the same year. There is a memorial to him in the north vestibule of St James's Church, Piccadilly.