Percy Eded Glading ( 29 November 1893 – 15 April 1970) was an English communist and a co-founder of the Communist Party of Great Britain (CPGB). He was also a trade union activist, an author, and a spy for the Soviet Union against Britain, an activity for which he was convicted and imprisoned. He was eventually arrested in January 1938 in the act of exchanging sensitive material from the Royal Arsenal at Woolwich. Predominantly due to the testimony of "Miss X", Glading was found guilty and sentenced to six years of hard labour.