Bang Mun Nak (Thai: บางมูลนาก, pronounced [bāːŋ mūːn nâːk]) is a district (amphoe) in the southern part of Phichit province, central Thailand.

Bang Mun Nak was the location of the Mueang Phum, an ancient town believed to be part of Phichit Province.

[1] Neighboring districts are (from the west clockwise): Pho Thale, Taphan Hin, Thap Khlo, Dong Charoen of Phichit Province; Nong Bua and Chum Saeng of Nakhon Sawan province.

Bang Mun Nak is about 52 km (32 mi) south of Mueang Pichit.

Bang Mun Nak is regarded as one of the three districts of Phichit, with a railroad running through (northern line).