Mazar-i-Sharīf (Pashto, Dari: مزار شریف, lit. 'noble shrine'), also known as Mazar-e Sharīf or simply Mazar (Pashto, Dari: مزار, lit. 'shrine'), is the fifth-largest city in Afghanistan by population, with the estimates varying from 500,000-680,000. It is the capital of Balkh province and is linked by highways with Kunduz in the east, Kabul in the southeast, Herat in the southwest and Termez, Uzbekistan in the north. It is about 55 km (34 mi) from the Uzbek border. The city is also a tourist attraction because of its famous shrines as well as the Islamic and Hellenistic archeological sites. The ancient city of Balkh is also nearby.

The region around Mazar-i-Sharif has been historically part of Greater Khorasan and was controlled by the Tahirids followed by the Saffarids, Samanids, Ghaznavids, Ghurids, Ilkhanids, Timurids, and Khanate of Bukhara until 1751 when it became part of the Durrani Empire (although under autonomous emirs). Eventually the city passed to a few local rulers before becoming part of Afghanistan in 1849.

Mazar-i-Sharif is the regional hub of northern Afghanistan, located in close proximity to both Uzbekistan and Tajikistan. It is also home to an international airport. It has the highest percentage of built-up land (91%) of all the Afghan provincial capitals, and it has additional built-up area extending beyond the municipal boundary but forming a part of the larger urban area. It is also the lowest-lying major city in the country, about 357 metres (1,171 ft) above sea level. The city was spared the devastation that occurred in the country's other large cities during the Soviet–Afghan War and subsequent civil war, and was long regarded as one of the safest cities in the country.

On 14 August 2021, Mazar-i-Sharif was seized by Taliban fighters, becoming the twenty-fifth provincial capital to be captured by the Taliban as part of the wider 2021 Taliban offensive.

The name Mazar-i-Sharif means "tomb of the saint", a reference to the purported tomb of Ali, cousin, son-in-law and companion of the Islamic prophet Muhammad. The tomb is housed in the large, blue-tiled sanctuary and mosque in the center of the city known as the Shrine of Ali or the Blue Mosque.

The Achaemenids controlled the region from the sixth century BCE. Alexander the Great conquered the area but it was then incorporated into the Seleucid Empire after his death. The decline of the Seleucids consequently led to the emergence of the Greco-Bactrian kingdom. Around 130 BCE, the Sakas occupied the region and the Greco-Bactrian kingdom fell. The Yuezhi took Mazar-i-Sharif and the surrounding area which led to the creation of the Kushan Empire. The Sasanians subsequently controlled the area after the fall of the Kushans. The Islamic conquests reached Mazar-i-Sharif in 651 CE.

The region around Mazar-i-Sharif has been historically part of Greater Khorasan and was controlled by the Tahirids followed by the Saffarids, Samanids, Ghaznavids, Ghurids, Ilkhanids, Timurids, and Khanate of Bukhara.

The poet Jalal al-Din Rumi was born somewhere in this area. His father Baha' Walad was descended from the first caliph Abu Bakr.