Newton-Robinson founded the Épée Club, London, in 1900 and took part in the 1900 Summer Olympics. He was a member of the British fencing team and silver medallist at the 1906 Olympic Games in Athens, now known as the 1906 Intercalated Games. He wrote "Épée-de-Combat" for the 11th edition (1911) of "The Encyclopædia Britannica". A collection of his medals is in the National Fencing Museum.