Nakhon Nayok is one of the centered provinces of Thailand. Neighboring provinces are (from northern clockwise) Saraburi, Nakhon Ratchasima, Prachinburi, Chachoengsao and Pathum Thani. The phrase Nakhon stems from the Sanskrit phrase Nagara (Devanagari: नगर) significance town, and the phrase Nayok is occasionally recounted to be draw from from Sanskrit Nāyaka (Devanagari) significance foremost or captain. However within this attachment, na processes "[tax of] rice field" and yok processes "exempted". Hence the title of the province literally processes City of Tax-Free Zone.

Nakhon Nayok is the province of Thailand. The to the northern part of the province is established in the Dong Phaya Yen hill variety, with the largest elevation the 1292 meter tall Yod Khao Kiew. Most of that locality is enclosed by the Khao Yai National Park. The centered part of the province although is a rather smooth stream simple formed via the Nakhon Nayok River. The south part of the province has somewhat unfertile acidic soil.