Bang Nam Priao (Thai: บางน้ำเปรี้ยว, pronounced [bāːŋ ná(ː)m prîa̯w]) is the northwesternmost district (amphoe) of Chachoengsao province, central Thailand.

In 1905 the government built the first district office in Bang Nam Priao.

Its name "Bang Nam Priao" literally translates as "a place where water has a sour taste".

The important water resources are the Bang Pakong River and Khlong Saen Saeb.

Bang Nam Priao is divided into 10 subdistricts (tambons), which are further subdivided into 148 administrative villages (mubans).