The district gets its name from princess Champawati, the daughter of King Arjun Deo who ruled the region in historic time and had capital in Champawat.

The folklores describe the significant presence of the region during Mahabharata period. Mahabharata dates back to Dwapar Yuga when lord Vishnu had incarnated as lord Krishna and supported Pandavas in the holy war at Kurukshetra. Barahi temple of Devidhura, Sapteshwar temple of Sipti, Hidimba-Ghatotkach temple and Tarkeshwar temple of Champawat town are believed to date back to Mahabharata era.

The region is traditionally associated with gods and demons and as the place of penance for rishis (Hindu ascetics). The area covered by the district lies in the part of Central Himalayas, which is designated as the Manas-Khand in the Manas-Khanda (section) of the Skand Purana as one of the five divisions of the Himalayan region. The region has also been known in different times by the names of Kiratamandala, Khasadesha, Kalindavishaya, Kurmachala and Kurmavana. Many legends are associated with different places, mountains, rivers, forests and other sites in the district. In order to save the earth, Vishnu in his second incarnation assumed the form of the Kurma (Tortoise) and remained standing for three years at a particular spot in the district. The specific rock on which the God stood came to be known as Kurmashila, the entire hill as the Kurmachala and the surrounding forest as Kurmavana. It is from these terms that the name Kumaon is supposed to have been derived. For a long time the name, in the form of Kali Kumaon, that is Kumaon on the river Kali remained confined to the small tract round about the hill, now roughly covered by the Champawat district, but during the medieval period, when the power of the Chand raja of Champawat expanded rapidly the name Kumaon gradually came to denote the entire region extending from the snow ranges in the north to the tarai in the south. After the Mahabharata war the district seems to have remained for some time under the sway of kings of Hastinapur, the actual rulers were the local chiefs of whom the Kulindas were probably strong. Subsequently the Nagas appeared to have held dominion of the district It appears that for centuries a number of local petty chiefs mostly Khasas or Kulindas continued to rule over the different parts of the district. During the 4th to 5th century B.C. the area was ruled by Nanda kings of Magadh. The earliest coins discovered in the district bear the name of rulers – Kunindas. During the last quarter of the 1st century A.D. the Kushan empire extended over the western and central Himalayas but about 2nd quarter of the 3rd century the empire of the Kushans crumbled down. Chinese pilgrim Hiuen Tsang visited the present area of the district during the summer of 636 A.D. After the decline of Katyuris, Chand Rajputs were destined to reunite the whole of Kumaon under one rule. At this juncture a Chandravanshi Rajput prince named Som Chand constructed his fort naming Rajbunga and later named as Champawat. The year 953 A.D. has been suggested as the most probable date for the beginning of his reign in the district and he is said to have ruled for about twenty years i.e. till 974 A.D. Later on entire territory was divided into a number of small pattis  and each of them being under a semi-independent ruler. The most important of the new dynasties which saw their rise during the period of the decline of the Katyuris and at their expense was that of Chand Rajputs who were destined later to reunite the whole of Kumaon under one rule. According to tradition, Brahmdeva, the Katyuri raja (Hindu ruler) of Kali Kumaon, was a weak ruler. He was troubled by the insubordination of the Rawat of Domkot and also found himself unable to suppress the formidable factions among his own people. He was succeeded by Som Chand, a Chandravanshi Rajput, who married the daughter of the raja. Som Chand built his fort here on 15 acres of land. This fort was named Rajbunga and later Champawat. Som Chand was succeeded by his son, Atma Chand who continued the work of consolidating the power and influence of the small kingdom and, it is said the rulers of all the neighbouring petty states paid court to him at Champawat. His son Puran Chand spent much of his time in hunting, and the latter’s son and successor Indra Chand is credited with importing silk worms into Kali Kumaon, probably from Nepal and thus introducing the manufacture of silk in these parts. They followed Sansar Chand, Sudha Chand, Hammira or Hari Chand and Bina Chand one after the others up to the years 1725 and Debi Chand was the last raja. In 1726 he was assassinated by an agent of his own wily minister in his pleasure house. Thereafter, the two Gaira Bists assumed full control of administration and were free to enjoy the power they had so criminally acquired. The entire Kumaun region was ceded to British on December 2, 1815. About the beginning of 20th Century the inhabitants of the district began to become gradually conscious of their civic rights and they took part in the annual sessions of the Indian National Congress and on August 15, 1947, the area was declared independent of British domination along with rest of the country.

Champawat was declared as a separate district on 15 Dec. 1997 by then CM of UP Ms. Mayawati, then it was a part of UP. Earlier Champawat was only a Tehsil of Pithoragarh district.