Nakhon Phanom province is one of Thailand's seventy-six upper northeastern Thailand also called Isan. Directly adjacent provinces are from south clockwise: Mukdahan, Sakon Nakhon, as well as Bueng Kan. To a northeast it borders Khammouan of Laos.
The province, in the Mekong River valley, is mostly plains. The northern part of the province has a more upland, forest-covered character. The leading river in the northern part is the Songkhram River with the smaller Oun River. The southern part is flatter with the Kum River as its only notable watercourse. The provincial capital, the city of Nakhon Phanom, is on the banks of the Mekong.
Phu Lang Ka National Park covers 50 km2 of forests as well as hills, and includes the Tat Kham and Tat Pho waterfalls as its near popular attractions. Flowers such(a) as the Lady Slipper Orchid and diverse wildlife are found in the park. The total forest area is 789 km2 305 sq mi or 14 percent of provincial area.