The Duchy of Poznań (Polish: Księstwo poznańskie; Latin: Ducatus Posnaniensis) was a feudal district duchy in the Greater Poland, centered on the Poznań Land.

The state was established in 1177, in the partition of the Duchy of Greater Poland, after the rebellion against Mieszko III.

Duke Odon of the Piast dynasty become its first ruler.

[1] It existed until 1279, when, it got united with duchies of Gniezno and Kalisz, under the rule of Przemysł II, forming the Duchy of Greater Poland.

[2] It remained a fiefdom within the Duchy of Poland, until 1227, and after that, it become an independent state.