The area of the present district was a significant part of the Chutiya Kingdom from 12th to 16th century. The name of Lower Dibang Valley is taken from the mighty river Dibang that flows through the heart of district and finally ends into the Brahmaputra. Before the year 1914, the district was a part of the Lakhimpur district. In June 1980, Dibang Valley district was created after it carved out from the Lohit district. On 16th December 2001, Dibang Valley district was divided into two parts namely Dibang Valley district and Lower Dibang Valley district. On that same date its administrative headquarter was declared at Roing as per the Amendment of Re-organization of the District Act of 1980.

Jomin Tayeng was the first person who direct recruited as Officer of the Indian Administrative Service from Arunachal Pradesh in 1968. In 1976 he became the secretary to the Chief Minister of Arunachal Pradesh. In 2004, he entered in politics after his retirement.

Geographically, the district has a total area of 13,029 sq. km. area and occupies the rank 1st in State and 30th in India on the bases of this size. It lies at 28°14'N latitude, 95°84'E longitude and 390 m altitude. In the year 2021, there was a total 69.69% forest area of total geographical area. It is surrounded by the Dibang Valley District in the North, Tinsukia District of Assam in the South, Lohit District in the East and East Siang District, Upper Siang District in the West. The major rivers that flow in the district are Dibang, Deopani, Iphi-pani, Eze, Diphu Nallah, Abha Pani, Dotung and Sisiri. The climate of the district remains pleasant almost throughout the year. Most of its rainfall occurs in the monsoon season. The actual rainfall in the district was 3435.1 mm in the year of 2021-22.

Administratively, the district is divided into 6 sub-districts, 1 town and 314 villages. English is its administrative language. The district came into existence on 16th December, 2001. It has administrative headquarters located at Roing which is situated at the distance of 358 kms from the State Capital. Lower Dibang Valley. There are total 2 legislative assembly constituencies in the district namely Dambuk and Roing. Both are the part of the Arunachal East Lok Sabha constituency.

Demographically, according to the 2011 census, the district has a total number of 10,883 households with a total population of 54,080 comprising 28,053 are males and 26,027 are females which leads it to rank 12th in the state and 630 in India. The density of population of the district is 6 (persons per sq km.). The sex ratio is pegged at 928 (females per 1000 males) while the child ratio stands at 948 (females per 1000 males). The schedule tribe population of the district is recorded as 25,974 including 12,649 are males and 13,325 are females. The percentage of Schedule Tribe is 2.73%. As per 2011 census the major religions in the district are Hindu and Christian with 53.47% and 17.04% of the total population. The population growth rate during the period of 2001-2011 was 7.20% including 3.30% were males and 11.74% were females. According to 2011 census the principal languages in the district are Adi and Nepali with 25.38% and 24.29%. In the year 2020 the number of live births in the district was 1,279 out of which 592 were males and 687 were females. In the same year the number of deaths in the district was 110 out of which 70 were males and 40 were females.

Economically, the main agricultural products in the district are paddy, maize, mustard, millet, etc. Orange, banana, ginger, pears, pineapple, papaya are major horticultural products in the district. There are some small scale industries of woolen, silk & artificial thread based clothes, ready-made garments, tailoring & embroidery, wood/wooden based furniture and agro based industries.

Education wise, according to the 2011 census, the district has a literacy rate of 69.13% including 75.55% are males and 62.19% are females. The total population of literate people is 31,849 comprising 18,087 are males and 13,762 are females. The total number of illiterates in the district is 22,231 comprising 9,966 are males and 12,265 are females. Some of the most reputed educational institutions are Government Secondary School, Kendriya Vidhyalaya, Jawahar Navodaya Vidyalaya, Higher Secondary School, Middle School, Primary School, Pre-Primary School, Middle School (Private), Primary School (Private), Central School, Vivekanada Kendra Vidyalaya, Industrial Training Institute, A.P. Forest Training School, Distance Institute for Educational Training, etc.

Gum Tayeng is the member of the Indian National Congress. In 2013, she became the Member of Legislative Assembly. Mukut Mithi is the member of Rajya Sabha. He also served as the Chief Minister of the Arunachal Pradesh from 1999 to 2003. He was a MLA from 1983 to 2006. In 2006, he became the Lieutenant Governor of Puducherry.

The District has several famous places to visit. These places are Mayudia, Mehao Lake, Mehao Wildlife Sanctuary, Sally, Nehru Van Udyan (Forest Park), Iphipani, Nijomaghat, Hunli, Bhismaknagar, Rukmini Nati, Ita and Padum Pukhuri, Kampona Pond. A number of tourists visit here every year from the worldwide. Mayudia gets snowfall from December to March which is the main attraction for tourists. It is also famous for trekking and greenery. Mehao Lake is a vast lake with absolutely clear water, a number of wild ducks and the surrounding of different flora and fauna. Trekking is also available here. It is Low Nutrient Lake. No fish is available in the Lake. Mehao Wildlife Sanctuary is named after the Mehao Lake. It is a natural forest with full of wildlife. Nehru Van Udyan is a park and a picnic spot. It is well maintained. There are beautiful orchid and cactus houses. Hunli is a beautiful valley. Bhismaknagar fort is the oldest historical monument in the district. Rukminati or the ruins of Princess Rukmini is located in Chimiri village. It is a hill fort belongs to the 14th/15th century. Ita and Padum Pukhuri is a historical pond built with bricks, located at Ithili village. Kampona Pond is located in Idili village. According to the Adi belief, it is the abode of Nag Raja.