The Principality of Nitra (; ), also known as the Duchy of Nitra, was a Slavic polity encompassing a group of settlements that developed in the 9th century around Nitra in present-day Slovakia. Its history remains uncertain because of a lack of contemporary sources. The territory's status is subject to scholarly debate; some modern historians describe it as an independent polity that was annexed either around 833 or 870 by Principality of Moravia while others say that it was under influence of the neighbouring Slavs from Moravia from its inception. No final list of the princes or dukes of Nitra has been agreed upon by historians.