Samuel "Sam" Vimes is a fictional policeman from Terry Pratchett's Discworld series. His full name and title is His Grace, The Duke of Ankh, Commander Sir Samuel Vimes. Other titles include His Excellency, Ambassador for Ankh-Morpork, as well as Blackboard Monitor Vimes.[1] He first appeared in the novel Guards! Guards!. While no detailed description of his physical appearance shows up in any of the Discworld novels, Pratchett says in the companion work, The Art of Discworld, that he has always imagined Vimes as British actor Pete Postlethwaite.

Vimes is the Commander of the City Watch, the burgeoning police force of the Discworld's largest city, Ankh-Morpork. His rise from alcoholic policeman to respected member of the aristocracy, and the growth and development of the Watch under his command, have together been one of the major threads of the Discworld series. Born into poverty, he is now a highly reluctant member of the nobility; both a knight and a duke, and married to Sybil Ramkin, the richest heiress in the city.