Ruja Plamenova Ignatova ; born 30 May 1980) is a Bulgarian-born German citizen and convicted fraudster. She is best known as the founder of a fraudulent cryptocurrency scheme known as OneCoin, which The Times has described as "one of the biggest scams in history". She is the subject of the 2019 BBC podcast series The Missing Cryptoqueen and the 2022 book of the same name.
