Castellnou de Seana is a village in the province of Lleida, within the autonomous community of Catalonia, Spain.
It is located in the western part of Catalonia, in the comarca of Pla d'Urgell. Like other settlements in this inland area of Lleida, it lies in a predominantly agricultural landscape.
The village is one of several small municipalities that make up the Pla d'Urgell district, a flat plain region centred on the town of Mollerussa.