Chaplin was a British hereditary peer, an amateur zoologist and musician. He was born in 1906, the son of Eric Chaplin, 2nd Viscount Chaplin, and the Hon Gwladys Wilson, daughter of Charles Wilson, 1st Baron Nunburnholme and Florence Wellesley. He was educated at Radley College.
During 1935 and 1936 he went on a zoological expedition to New Guinea. He was Secretary of the Zoological Society of London between 1952 and 1955, and a member of the council.
Chaplin studied musical composition in Paris with Nadia Boulanger between 1936 and 1939. He served as an Officer in the Royal Air Force from 1940 until 1946, achieving the rank of Flight Lieutenant. He succeeded his father as 3rd Viscount Chaplin in 1949.
He was married in 1933 to Alvilde Bridges, and they had one daughter. The married was dissolved in 1950, and in 1951 he married the Hon Rosemary Lyttelton and they had two daughters. Chaplin died in 1981 in Belgravia, London, when in the absence of male heirs, the viscountcy became extinct.