<Tr> <Th> Parent (s) </Th> <Td> Keith Allen Alison Owen </Td> </Tr> <Tr> <Th> Relatives </Th> <Td> Lily Allen (sister) Kevin Allen (uncle) </Td> </Tr> <P> Alfie Allen (born 12 September 1986) is an English actor . He is best known for portraying Theon Greyjoy in the HBO series Game of Thrones since 2011 . </P> <P> Allen was born in Hammersmith, London, the son of film producer Alison Owen and Welsh - born actor Keith Allen . His older sister is singer Lily Allen; her song "Alfie" is about him . He went to Windlesham House School in Sussex, Embley Park School near Romsey, St John's College in Portsmouth and the Fine Arts College in Hampstead, where he studied for his A-levels . He is also a third cousin of British singer Sam Smith . </P>

Who plays theon greyjoy on game of thrones