Olga Isabel Gray (28 November 1906 – 19 July 1990) was an English secretary and typist who acted as a double agent in the 1930s after being recruited by MI5 to infiltrate British communist groups.

Then, after a period of working for the Anti-War Movement, she was approached by Harry Pollitt and asked to undertake a 'special mission', on behalf of the Communist Party of Great Britain (CPGB).

[2] Having accepted the request, Gray was sent to Paris on 6 June 1934; she was to rendezvous with Percy Glading, an officer of League Against Anti-Imperialism and a founding member of the CPGB.

[2] However, the cover story provided to Gray by the CPGB was so flimsy for a woman travelling alone during the monsoon season to India that she would easily rouse the suspicion of the authorities.

[2] On 21 January Gray rang the authorities to report that Glading was to meet a man at Charing Cross station at 8.15 pm to receive still more classified documents.