Melita Stedman Norwood, née Sirnis, (25 March 1912 – 2 June 2005) was a British civil servant, KGB intelligence source who, for a period of about 40 years following her recruitment in 1937, supplied the KGB (and its predecessor agencies) with state secrets from her job at the British Non-Ferrous Metals Research Association . Her KGB handlers gave her the codename "Hola". She was considered "the most important female agent ever recruited by the USSR."

Norwood was born to a Latvian father, Alexander Sirnis, and a British mother Gertrude, née Stedman, in Pokesdown, Hampshire (now Dorset). Both her parents were active in socialist circles. In 1935 she married Hilary Norwood (1910-1985), the schoolteacher son of Russian parents (his name had originally been Nussbaum) and a lifelong communist. A convinced communist herself, she apparently gained no material profit from her actions. When asked about her motives, she explained: "I did what I did, not to make money, but to help prevent the defeat of a new system which had, at great cost, given ordinary people food and fares which they could afford, a good education and a health service." Her espionage activities were first publicly revealed by Vasili Mitrokhin in 1999. At that time, it was also revealed that the British authorities had known about her status only since Mitrokhin's defection in 1992, despite the fact that she was well known to be a communist sympathizer, but had decided not to act to avoid tipping their hand. Norwood was never prosecuted for her actions.