Maisie Williams as Lydia Lamont

Maxine Peake as Eileen Lamont

Greta Scacchi as Miss Edith Mantel

Monica Dolan as Miss Martha Alvaro

Mathew Baynton as Mr. Hopkins

Florence Pugh as Abbie Mortimer

Joe Cole as Kenneth Lamont

Morfydd Clark as Miss Pamela Charron

Anna Burnett as Susan

Hannah Rose Caton as Titch

Evie Hooton as Janet

Katie Ann Knight as Connie

Lauren McCrostie as Gwen

Elizabeth Marsh as Miss Fanshawe

Hannah Stokely as Miss Ash

Guy Morris as Teacher #1

Katherine Peat as Teacher #2

Ben Kerfoot as Bike Boy

Jiggy Bhore as Mrs. Maud Leece

Crissy O'Donovan as School Nurse

Simon Paisley Day as Psychiatrist

Ellie Bamber as Schoolgirl #2