The main cast of the British spy thriller series "Slow Horses" includes:
- Gary Oldman as Jackson Lamb, the unkempt, rude, and sharp-witted head of Slough House.
- Jack Lowden as River Cartwright, an ambitious MI5 agent sent to Slough House after a public blunder.
- Kristin Scott Thomas as Diana Taverner, Deputy Director General of MI5 and head of operations.
- Sophie Okonedo as Ingrid Tearney, Director General of MI5 (series 3 and guest appearances).
- Jonathan Pryce as David Cartwright, River's grandfather and retired senior MI5 officer.
- Hugo Weaving as Frank Harkness, a former CIA operative (series 4).
- Saskia Reeves as Catherine Standish, office administrator and recovering alcoholic.
- Rosalind Eleazar as Louisa Guy, assigned to Slough House after a failed operation.
- Christopher Chung as Roddy Ho, the tech expert and former hacktivist.
- Aimee-Ffion Edwards as Shirley Dander, with anger and drug issues.
These actors and characters form the core team involved in the espionage activities of Slough House, a department for MI5 agents who have made career- ending mistakes but continue to work on investigations.
