Meknes (Arabic: مكناس, romanized: maknās, pronounced [maknaːs]) is one of the four Imperial cities of Morocco, located in northern central Morocco and the sixth largest city by population in the kingdom. Founded in the 11th century by the Almoravids as a military settlement, Meknes became the capital of Morocco during the reign of Sultan Ismail Ibn Sharif (1672–1727), son of the founder of the Alaouite dynasty. Sultan Ismail created a massive imperial palace complex and endowed the city with extensive fortifications and monumental gates. The city recorded a population of 551,503 in the 2024 Moroccan census. It is the seat of Meknès Prefecture and an important economic hub in the region of Fès-Meknès.

Meknes is named after an Amazigh (Berber) tribe historically known as the Miknasa (Imeknasen in Amazigh languages).

Volubilis, a major Roman-era settlement in Morocco and one of its early urban centres, is located near the site of the current city of Meknes. The current city and its name, however, originate with a Berber tribe called the Miknasa who settled this region around the 10th century. A group of small unfortified Miknasa villages known as miknāsat al-zaytūn were established here in the 10th century. The Almoravids founded a fortress or fortified settlement just south of these villages after conquering the area in the 11th century. Originally called Tagrart or Taqrart, this Almoravid settlement formed the beginnings of what is now the old medina of Meknes. The Nejjarine Mosque, often reputed to be the oldest mosque in the city, dates back to the Almoravid period and may have served as the central mosque of the Almoravid settlement. The mosque that became the present-day Grand Mosque of Meknes is believed to have been first built by the Almoravids in the 12th century.

The fortress resisted the military advance of the Almohads, who destroyed the city after a long siege in the 12th century. However, at the beginning of the 13th century the Almohad caliph Muhammad al-Nasir (ruled 1199–1213) rebuilt the city and its fortifications, as well as its Grand Mosque. The city enjoyed relative prosperity in this period, before being conquered again by the new Marinid dynasty in 1244. The first kasbah (citadel or governor's district) of Meknes was created afterwards by sultan Abu Yusuf Ya'qub in 1276 CE – the same year that the citadel of Fes el-Jdid was built in nearby Fes, the new capital. During this period, Meknes was frequently the residence of Marinid princes (often appointed there as governors) and especially of viziers. The Mosque of the Kasbah (the later Mosque of Lalla Aouda) was also founded and first built in 1276. The Marinids also carried out major restorations to the Grand Mosque in the 14th century and built the major madrasas of the city near it. The latter included the Bou Inania Madrasa (built in 1336) and two other madrasas, Madrasa al-Qadi and Madrasa Shuhud, all built by Sultan Abu el-Hassan.

After the end of the Marinid and Wattasid periods, however, Meknes suffered from neglect as the new Saadian dynasty (16th and early 17th century) focused their attention on their capital at Marrakesh and neglected the old northern cities of Morocco.

It wasn't until the Alaouite dynasty in the second half of the 17th century that Meknes received renewed attention. Under Moulay Rashid (ruled 1666–1672), the first Alaouite sultan to unite Morocco under his rule, Fes became the capital once more and his brother, Moulay Isma'il ibn Sharif, governed Meknes. Upon Rashid's death in 1672, Moulay Isma'il became sultan and chose Meknes as his new capital. In addition to his possible attachment to the city as a governor, a number of reasons may have favoured this choice. One may have been the fact that Ismail had to fight hard to reconquer both Fes and Marrakesh from his rival nephew (Ahmad al-Mahriz, son of Moulay Rashid) during the first years of his reign, which may have rendered him skeptical towards both cities as possible centers of power. Moreover, Moulay Rashid had garrisoned much of Fes with his own contingents from the Tafilalt and eastern Morocco while Moulay Isma'il was forming his own personal royal guard composed of Black slaves ('abid) from Sub-Saharan Africa, and there may have been concerns that not all these contingents could be garrisoned simultaneously in Fes. The ulema (religious scholars) of Fes were also particularly disapproving of his ways, including his use of slaves (many of whom were of Muslim background), and maintained tense relations with him throughout his reign. Choosing Meknes thus removed him from the influence of traditional elites and allowed him to build a fresh base from which he hoped to exercise absolute power. The threat of Ottoman attacks from the east (from Algeria) and the increasing insecurity in central Morocco due to tribal migrations from the Atlas and Sahara regions may have also persuaded Ismail that Meknes, situated further west, was more defensible than Fes.

Whatever the reasons, Ismail made Meknes the center of Morocco in his time and he embarked on the construction of a new monumental palace-city on the south side of the old city. Its construction continued throughout the 55 years of his reign, beginning immediately after his accession to the throne in 1672. Existing structures dating from the earlier medieval kasbah of the city were demolished to make way; the name of the large public square in front of the Kasbah today, el-Hedim (or Place el-Hedim), means "the rubble" and came from the masses of rubble and debris which were piled here during the demolition. Labour was carried out by paid workers as well as by contingents of slaves, particularly Christian prisoners of war. Estimates on the total number of workers involved range from 25,000 and 55,000. Nonetheless, frequently-told stories about the tens of thousands of Christian slaves used for labour and the large underground dungeons where they were kept are somewhat exaggerated and originate from the accounts of European ambassadors who visited Isma'il's court (often to negotiate the release of prisoners from their countries). In reality, the number of Christian slaves was likely closer to a few thousand at most and the chambers popularly called "prisons" were actually storage rooms for grain and supplies.

It was also in Moulay Ismail's reign that the Jewish inhabitants of the city were moved to a new Mellah or Jewish district to the west, near the Kasbah, not unlike the Mellah of Fes or that of Marrakesh. The Mellah was located between the old medina, west of Place el-Hedim, and the more outlying quarter of Madinat al-Riyad al-Anbari. Both the Mellah and Madinat ar-Riyad were part of an urban extension ordered by Isma'il in the western angle between the old city and the Kasbah. Moulay Isma'il also undertook works throughout the old city too. He refortified the walls and built new monumental city gates such as Bab Berda'in and Bab Khemis. He also built several other kasbahs or garrison forts throughout the city to house his 'abid troops and help protect (and control) the rest of the town, such as the Kasbah Hadrash and the Kasbah Tizimi. He carried out renovations to the Grand Mosque and the nearby Madrasa al-Qadi (which he devotes to students from the Tafilalt), and founded the Zitouna Mosque. Khnata bent Bakkar, one of his wives who was vizier (minister) under him (and briefly became de facto ruler of Morocco in 1728 after his death), was responsible for founding the Bab Berda'in Mosque, completed in 1709.