Crusader Kings III is a grand strategy game set in the Middle Ages, developed by Paradox Development Studio and published by Paradox Interactive as a sequel to Crusader Kings and Crusader Kings II.

The game, like its predecessors Crusader Kings and Crusader Kings II, is a dynasty simulator set in the Middle Ages, and is expected to run from the Viking Age to the Fall of Byzantium. Dynasties can form cadet branches that have their own heads and act mostly independently from their parent dynasty. The heads of dynasties will be able to use a new resource known as Renown to assert their control over their house. For example, the heads of dynasties are responsible for legitimizing bastards.