Na Yai Am (Thai: นายายอาม, pronounced [nāː jāːj ʔāːm]) is a district (amphoe) in the western part of Chanthaburi province, eastern Thailand.

[2] Its name "Na Yai Am" directly translates as "grandma Am's rice field".

This was because here in the past was the residence and rice field of an old woman named Yai Am (grandma Am) and a place where people passed by.

The district is divided into six sub-districts (tambons), which are further subdivided into 67 villages (mubans).

There are a further six tambon administrative organizations (TAO) responsible for the non-municipal areas.