Champhai district is one of the eight districts of Mizoram state in India. The district is bounded on the north by Churachandpur district of Manipur state, on the west by Aizawl and Serchhip districts, and on the south and east by Myanmar. The district occupies an area of 3185.83 km². Champhai town is the administrative headquarters of the district.

Champhai district has a moderate climate. In winter the temperature varies from 10°C to 20°C and in summer, the temperature varies between 15°C and 30°C.

According to the 2011 census Champhai district has a population of 125,370, roughly equal to the nation of Grenada.This gives it a ranking of 610th in India (out of a total of 640). The district has a population density of 39 inhabitants per square kilometre (100/sq mi). Its population growth rate over the decade 2001-2011 was 16.01%. Champhai has a sex ratio of 984 females for every 1000 males, and a literacy rate of 95.91%.

In 1991 Champai district became home to Murlen National Park, which has an area of 200 km2 (77.2 sq mi).It is also home to the Lengteng Wildlife Sanctuary, which was established in 1999 and has an area of 120 km2 (46.3 sq mi).