The Testaments is out on 10 September and comes 33 years after the original book was nominated for the same award.
Jeanette Winterson and John Lanchester are among the others to be longlisted.
The only US author to be included is Illinois-born, Edinburgh-based Lucy Ellison, whose work Ducks, Newburyport is a 1,000-page novel that consists of a single sentence.
And just one debut novel is in the running – My Sister, The Serial Killer by Nigerian author Oyinkan Braithwaite.
The list will be whittled down to a shortlist of six on 3 September, with the winner to be announced on 14 October.
The longlist in full:
Margaret Atwood (Canada) – The Testaments (Vintage, Chatto & Windus)
Kevin Barry (Ireland) – Night Boat to Tangier (Canongate Books)
Oyinkan Braithwaite (UK/Nigeria) – My Sister, The Serial Killer (Atlantic Books)
Lucy Ellmann (USA/UK) – Ducks, Newburyport (Galley Beggar Press)
Bernardine Evaristo (UK) – Girl, Woman, Other (Hamish Hamilton)
John Lanchester (UK) – The Wall (Faber & Faber)
Deborah Levy (UK) – The Man Who Saw Everything (Hamish Hamilton)
Valeria Luiselli (Mexico/Italy) – Lost Children Archive (4th Estate)
Chigozie Obioma (Nigeria) – An Orchestra of Minorities (Little Brown)
Max Porter (UK) – Lanny (Faber & Faber)
Salman Rushdie (UK/India) – Quichotte (Jonathan Cape)
Elif Shafak (UK/Turkey) – 10 Minutes 38 Seconds in This Strange World (Viking)
Jeanette Winterson (UK) – Frankissstein (Jonathan Cape)