The Fife-born actor will play a wayward Edinburgh detective who stumbles into trouble when he goes on holiday to Florida.
Scott will portray Detective Inspector Ray Lennox, who becomes embroiled in a paedophile ring protected by corrupt American police officers.
Although much of the action will unfold in Miami, it will be intercut with flashbacks to Edinburgh and a previous abuse case the troubled detective was involved with.
The book is a sequel to Filth, which was adapted into a feature film three years ago, starring James McAvoy three years ago. Jamie Bell played the role of DI Lennox on screen.
Welsh said: “The story is a classic journey from darkness into light and, despite the troubling subject matter, I think an uplifting one.”
Plans for the TV series were unveiled at Mipcom, the world’s biggest entertainment market event at Cannes in France.
Producer Tony Wood said the drama, which is expected to be adapted into a six-part series, would be Welsh’s “toughest yet most life-affirming to date.”