Claude Whelan is a senior British intelligence official currently serving as Director-General of MI5.

Before the events of Season 4, Whelan was appointed as Director-General to replace Dame Ingrid Tearney, with Diana Taverner having served as Acting Director-General briefly in between. Before his appointment, he worked strictly in managerial roles within the service and was never deployed to the field. He is classed as a politically exposed person, and is referred to in intelligence reports by the Metropolitan Police using the codename Galahad.

Upon taking office, he appointed former Metropolitan Police officer Emma Flyte as MI5 Head of Security and leader of The Dogs, replacing the incapacitated Nick. He also sent Moira, a senior administrator at The Park, to Slough House.