It lies in lower northern Thailand, neighbouring the provinces of Kamphaeng Phet, Phichit, Phetchabun, Lopburi, Sing Buri, Chai Nat, Uthai Thani, and Tak (clockwise from north).

In the reign of King Taksin the Great, Phra Bang became a Siamese military base to prevent further Burmese attacks.

When King Mongkut signed the Bowring Treaty with Britain the glorious time of Nakhon Sawan began, as it became the main rice and teak trading centre.

It is responsible for defending the northwestern border with Burma, from Mae Hong Son in the north to Kanchanaburi in the south.

The swamp is directly east of the town Nakhon Sawan and extends into the districts of Tha Tako and Chum Saeng.

As of 26 November 2019 there are:[8] one Nakhon Sawan Provincial Administration Organisation (ongkan borihan suan changwat) and 21 municipal (thesaban) areas in the province.

The non-municipal areas are administered by 121 Subdistrict Administrative Organisations - SAO (ongkan borihan suan tambon).

[2] Nakhon Sawan lies on Route 1 (Phahonyothin Road), which runs from Bangkok through Ayutthaya and Saraburi before passing through Nakhon Sawan, then continues through Kamphaeng Phet, Lampang, and Chiang Rai until it reaches the border with Burma at Mae Sai.