Khyber Pakhtunkhwa (; Pashto: خیبر پښتونخوا‎; Urdu: خیبر پختونخوا‎), often abbreviated as KP or KPK and formerly known as the North-West Frontier Province, is one of the four provinces of Pakistan. It is located in the northwestern region of the country, along the Afghanistan–Pakistan border.

It was previously known as the North-West Frontier Province (NWFP) until 2010, when the name was changed to Khyber Pakhtunkhwa by the 18th Amendment to the Constitution of Pakistan, and is known colloquially by various other names. Khyber Pakhtunkhwa is the third-largest province of Pakistan in terms of both population and economy, though it is geographically the smallest of the four provinces. Within Pakistan, Khyber Pakhtunkhwa shares a border with the Islamabad Capital Territory, Punjab, Balochistan, and the Pakistani-administered territories of Gilgit-Baltistan and Azad Jammu and Kashmir. It is home to 17.9% of Pakistan's total population, with the majority of the province's inhabitants being ethnic Pashtuns and Hindko speakers.

The province is the site of the ancient kingdom of Gandhara, including the ruins of its capital Pushkalavati, located near modern-day Charsadda. Once a stronghold of Buddhism, the history of the region was characterized by frequent invasions by various empires due to its geographical proximity to the Khyber Pass.

On 2 March 2017, the Government of Pakistan considered a proposal to merge the adjoining Federally Administered Tribal Areas (FATA) with Khyber Pakhtunkhwa, and to repeal the Frontier Crimes Regulations, a set of British Raj-era special laws that continued to govern the tribal areas at the time. However, some political parties opposed the merger, and called for the tribal areas to instead become a separate province entirely. On 24 May 2018, the National Assembly of Pakistan voted in favour of an amendment to the Constitution of Pakistan to merge the Federally Administered Tribal Areas with Khyber Pakhtunkhwa. The Khyber Pakhtunkhwa Provincial Assembly then approved the historic FATA–KP merger bill on 28 May 2018, which would merge FATA with Khyber Pakhtunkhwa. The bill was then signed by erstwhile President Mamnoon Hussain, officially completing the process of this historic merger.