Jessie Buckley Marian Halcombe Actor Ben Hardy Walter Hartright Actor Olivia Vinall Laura Fairlie , Anne Catherick Actor Art Malik Erasmus Nash Actor Joanna Scanlan Mrs Vesey Actor Vicki Pepperdine Mrs Michelson Actor Kerry Fox Mrs Catherick Actor Nicholas Jones Mr Gilmore Actor Ivan Kaye Pesca Actor Sonya Cassidy Madam Fosco Actor Dougray Scott Sir Percival Glyde Actor Tony Flynn Mr Merriman Actor Riccardo Scamarcio Count Fosco Actor Charles Dance Mr Fairlie Actor James Flynn Louis Actor Ruth Sheen Mrs Clements Actor Cathy Belton Mrs Hartright Actor Neil Keery Vernon Actor Clare Mcmahon Fanny Actor Cole Curran Robert Actor Fiona Seres Writer David M. Thompson Executive Producer Sarah Curtis Producer Carl Tibbetts Director Joanie Blaikie Executive Producer Mona Qureshi Executive Producer