Nong Ya Plong (Thai: หนองหญ้าปล้อง, pronounced [nɔ̌ːŋ jâː plɔ̂ŋ]) is a district (amphoe) in the northwestern part of Phetchaburi province, western Thailand.

Nong Ya Plong was established as a minor district (king amphoe) on 16 July 1972, when three tambons, Nong Ya Plong, Yang Nam Klat Nuea, and Yang Nam Klat Tai were split off from Khao Yoi district.

[2] Neighboring districts are (from the north clockwise) Ban Kha and Pak Tho of Ratchaburi province, Khao Yoi, Ban Lat, and Kaeng Krachan of Phetchaburi Province.

The district is divided into four sub-districts (tambons), which are further subdivided into 31 villages (mubans).

There are no municipal areas (thesaban), and three tambon administrative organizations (TAO).