Khyber Pakhtunkhwa, formerly North-West Frontier Province, province and historic region (1998 pop. 17,554,674), c.41,000 sq mi (106,200 sq km), NW Pakistan, bounded on the N and W by Afghanistan. Peshawar is the capital. An area of high, barren mountains dissected by fertile valleys, it is predominantly agricultural. Wheat is the chief crop; barley, sugarcane, tobacco, cotton, and fruit trees are also cultivated, and livestock is raised. Irrigation works supplement the scanty rainfall. Mineral resources include marble, rock salt, gypsum, and limestone. There are some mountain forests. Food processing, cotton and wool milling, papermaking, and the production of cigarettes, textiles, chemicals, and fertilizer are the main industries; handicrafts also flourish. Pathans constitute about two thirds of the population.

The region has been historically and strategically important due to passes leading into India, through which came invaders from central Asia. Alexander the Great conquered the region c.326 BC, but his garrisons were unable to hold the region. In the early centuries AD, Kanishka and his Kushan dynasty ruled the area. The Pathans arrived in the 7th cent., and by the 10th cent. conquerors from Afghanistan had made Islam the dominant religion. Under local Pathan rule from the late 12th cent. until Babur annexed it to his Mughal empire, the region paid nominal allegiance to the Mughals in the 16th and 17th cent. After Nadir Shah's invasion (1738), it became a feudatory of the Afghan Durrani kingdom. The Sikhs later held the area, which passed to Great Britain in 1849. The British maintained large military forces and paid heavy subsidies to pacify the Pathan resistance.

Britain separated the region from the Punjab of India in 1901 and constituted the North-West Frontier Province, whose people voted to join newly independent Pakistan in 1947. Following the absorption of the North-West Frontier Province into Pakistan, neighboring Afghanistan engendered the Pushtunistan Controversy (see Afghanistan). From 1955 to 1970 the North-West Frontier Province was a section of the consolidated province of West Pakistan. In 1970, the region was once again granted provincial status.

The Soviet invasion of Afghanistan caused over 3 million refugees to flee to the province. Peshawar became the military and political center of the Afghan anti-Soviet coalition. The Soviet withdrawal in 1989 raised hopes that the refugees would be repatriated. Although renewed factional fighting in 1992 threatened the process, all Afghan tented refugee camps were closed by 1995. The province was renamed Khyber Pakhtunkhwa in 2010; the change was unpopular with the province's non-Pashto-speaking minorities, especially the Hindkowans.