Lennie James was born in South London to Trinidadian parents. His mother, Phyllis Mary James, died when he was 12. Lennie and his older brother went into a council children's home. When he was 16 he was fostered with a social worker who had two older children, and they remain very close. Within a year Lennie began writing plays (Storm Damage was broadcast by the BBC in 2000 and won a Royal Television Society (RTS) award in 2001). Lennie received his training at the Guildhall School of Music & Drama from which he graduated in 1988.