Forna was born in Bellshill, Scotland, in 1964 to a Sierra Leonean father, Mohamed Forna, and a Scottish mother, Maureen Christison. When Forna was six months old the family travelled to Sierra Leone, where Mohamed Forna worked as a physician. He later became involved in politics and entered government, only to resign citing a growth in political violence and corruption. Between 1970 and 1973 he was imprisoned and declared an AmnestyPrisoner of Conscience. Mohamed Forna was hanged on charges of treason in 1975. The events of Forna's childhood and her investigation into the conspiracy surrounding her father's death are the subject of the memoir The Devil That Danced on the Water.
Between 1989 and 1999 Forna worked for the BBC, both in radio and television, as a reporter and documentary maker in the spheres of arts and politics. She is also known for her Africa documentaries: Through African Eyes (1995),Africa Unmasked (2002) and The Lost Libraries of Timbuktu (2009). Forna is also a board member of the Royal National Theatre and a judge for The Man Booker International Prize 2013.
Aminatta Forna is married to the furniture designer Simon Westcott and lives in south-east London.