Amnat Charoen (Thai: อำนาจเจริญ, pronounced [ʔām.nâːt tɕā.rɤ̄ːn]; Northeastern Thai: อำนาจเจริญ, pronounced [ʔàm.nâːt tɕā.lɤ̂ːn]) is one of Thailand's seventy-six provinces (changwat) and lies central northeastern Thailand, also called Isan. Neighbouring provinces are (clockwise from the south) Ubon Ratchathani, Yasothon, and Mukdahan. To the east it borders Savannakhet of Laos. Its name is a concatenation of อำนาจ ("authority, power") and เจริญ ("prosperous").

The province is in the Mekong valley. In dry season, from February to May, water in Mekong River declines, and allows islands to appear. Islands include Kaeng Tanglang at Si Sombun Village, close to Amphoe Chanuman, and Kaeng Hin Khan at Ban Hin Khan, 30 kilometres south of Amphoe Chanuman. The other two rivers in the province are the Lam Sae Bok and Lam Sae Bai. The total forest area is 314 km² (121 sq mi) or 9.5 percent of provincial area.

There is one national park, along with five other national parks, make up region 9 (Ubon Ratchathani) of Thailand's protected areas. (Visitors in fiscal year 2024)

Amnat Charoen gained city status during the reign of King Rama III. It was first administered from Nakhon Khemarat, and later from Ubon Ratchathani. It became a province in its own right on 12 January 1993, when it was split off from Ubon Ratchathani. It is thus one of the four newest provinces of Thailand, together with Nong Bua Lam Phu and Sa Kaeo, both also established in 1993, and Bueng Kan, established in 2011.

The province is overwhelmingly agricultural. In 2008, Amnat Charoen locals developed the so-called "Dhamma agriculture" model based on self-governance and aimed at making the province a hub for organic farming. According to the Office of Agriculture Economics, Amnat Charoen in 2016 had a total of 883,499 rai planted in hom Mali rice. Sugarcane plantations increased from 40,688 rai in 2015 to 51,446 rai in 2016.

In the Lue Amnat District the industries include Silk (ikat fabric), Khid fabric, Products processed from sedge mats, fish sauce, chili paste, and botanical arts. In the Mueang District the local industries include dried meat, fermented pork with star gooseberry leaves (Somporn Shop), Herbal Jaew Bong, Jasmin germinated brown rice, organic jasmine rice, Jasmine rice 3K, Mulberry Tea, Wood carvings, Sedge mats (khit pattern), Silky mats, Bananas wrapped in sesame seeds, Naturally dyed cotton, Plain fabric, Silk Shawl, Turtle scale pattern fabric, silk marbles, and steamed sticky rice boxing from Na Chik sub-district. Some local industries in the Phang district include, rain cloth, tie-die cloth, khit pattern cloth, sarong, silk fabric, and processed silk. In the Chanuman District some local industries include Dried Bananas from Ban Hin Khan, White towels with a woven edge, woven fabric, and Tamarind facial cleansers. In the Pathumratchawongsa District some local industries include Jasmine rice, Khat-ikat-mi-khit fabric, and the Ban Hin Kaeng Herbal Processing Group (Black Galingale Distilled Liquor). In the Senangkhanikhom District the local industry is sesame oil balm. In the Huataphan District the local industry is Ban Kham Phra woven fabric handicrafts.

In the middle of the provincial seal is an image of the Buddha called Phra Mongkol Ming Muang. Also known as Phra Yai (Big Buddha), this 20 m high statue is among the most sacred in the city of Amnat Charoen.

The provincial tree is Hopea ferrea. The provincial aquatic life is the Siamese mud carp (Henicorhynchus siamensis).