The district has a heterogeneous population with majority comprising of Naga tribes from all over the Nagaland.  There is sizable population of non-tribal living in the town areas. Although notified town of Dimapur district has remained the same, the neighboring villages /settlement have expanded considerably over the years merging with town boundary to form a length of more than 13 kms. In addition, there is sizeable rural population in the Sub-division of Niuland, Kuhuboto, Dhansiripar  and Medziphema blocks. The total population of the district as per 2001 census is 3, 08,382. The main factor contributing to large increase in population of the district is migration from other parts of state. There is also considerable migration from Assam.

Dimapur town is the commercial hub of the state and is the magnet around which the economic and developmental activities of the district are centered; it is one of the fastest developing township of the North East. The business of the town can trace their history to British times. The town is also a gateway to Nagaland and Manipur state. It is an important rail head and also has an airport. The National Highway 39 that connects Kohima, Imphal and Myanmar border of Moreh runs through Dimapur District.

Dimapur city, the major commercial hub in Nagaland, has a heterogeneous mix of people from all over India, and for which it is also known as "mini India." Besides the dominant Naga tribes who comprises about 50% of the city's population, other prominent groups include Bengalis, Assamese, Nepalese, Biharis, Marwaris, Punjabis and also Tamils and Keralites. In the last two decades, Tibetan traders have also settled in the city.

 In Dhansiripahar sub division, the tribes inhabiting the area is predominantly Angami, Sumi, Kachari and Chakhesang while in Medziphema sub division, the Angami tribe is predominant although a few Kuki and Sumi villages are also found. In Kuhuboto and Niuland sub divisions, the Sumis are the predominant tribe inhabiting the areas. All these tribes have their own customary laws which dominate their social life. The Village Councils are the local bodies through which such customary laws are enacted. The norms and traditions regarding marriage, divorce, inheritance, death etc are governed by such customary laws. Disputes regarding land, water and such resources and even personal disputes are very often resolved based on these customary laws.

In Dimapur district, all these tribes also celebrate their own indigenous cultural festivals. The following is a brief write up on the festivals of the major tribes that inhabit the district. The Angami tribe celebrates Sekrenyi in the month of February. It normally falls on the 25th day of the Angami month of Kezei. The ten-day festival is also called Phousanyi by the Angami's. The festivals follows a circle of ritual and ceremony, the first being “Kizie” followed by “Dsuseva” (touching the sleeping water) sacrifices are also made during this time.

Ahuna is a traditional post harvest festival of the Sumi tribe. Ahuna signifies the celebration of the seasons harvest's in thanks giving, while evoking the spirits for good fortune in the New Year Tuluni is a festival of great significance. The festival is marked with feast as the occasion occurs in the bountiful season of the year.

It may be mentioned that other tribes who have settled in Dimapur also celebrate their festivals with as much pomp and gaiety. The Ao tribe observes Moatsü Mong after the sowing is done. It provides the Aos a period of recreation after the strenuous job. The festival marked by vigorous songs and dances merry making and fun is now observed only for three days from 1-3 May.  The Aos have another festival called Tsungrem Mong celebrated on the eve of harvest from 1 to 3 August. These festivals provide opportunities to the building generation and village stalwart to demonstrate their intellectual skill and physical powers.

The Tokhu Emong is the harvest festival of the Lothas. Tokhu Emong is celebrated on November 7, every year. The main features of the feast are community songs, dances, feast fun and frolic. Tokhu Emong is also a festival of thanksgiving, sharing and reconciliation but the most beautiful aspect of this festival is that past rancor's are forgiven, new ties are formed and bonds of closer intimacy are formed.

The Chakhesang community celebrate the Suhkruhnye festival on15th January which is their most important festival. All the tribes celebrate their distinct seasonal festivals with much gaiety and community feasting. Most of these festivals revolve round agriculture, since it is the main-stay of Naga society. Over 85% population of Nagaland is directly dependent on agriculture and lives in a thousand and odd villages situated on high hill tops or slopes overlooking verdant valleys humming with murmuring streams.