Nuevo León, officially the Free and Sovereign State of Nuevo León, is a state in northeastern Mexico. The state borders the Mexican states of Tamaulipas, Coahuila, Zacatecas, and San Luis Potosi, and has an extremely narrow international border with the U.S. state of Texas. Covering 64,156 square kilometers (24,771 square miles) and with a population of 5.78 million people, Nuevo León is the thirteenth-largest federal entity by area and the seventh-most populous as of 2020.

Monterrey, the state's capital, is the most populous city in Nuevo León and the ninth-largest in Mexico. Monterrey is part of the Monterrey metropolitan area, the second-largest metropolitan area in the country with an estimated population of 5.3 million people in 2020. About 92% of the state's population lives in the metropolitan area.

Prior to European colonization, Nuevo León was home to various nomadic groups, known as chichimecas to the Spaniards. Stemming from Luis Carvajal y de la Cueva's expedition in 1580, the New Kingdom of León was established, encompassing present-day Coahuila, Nuevo León, Tamaulipas, and Texas, but permanent settlement did not occur until 1592. In 1824, Nuevo León became a state of Mexico following the country's successful war for independence. The state began industrializing in the late 19th century and early 20th century, establishing various large companies, which accelerated after the Mexican Revolution. Today, Nuevo León is a major manufacturing hub with one of Mexico's largest economies.

The origins of Nuevo León's name can be traced back to the late-16th century, when Spanish explorer Luis Carvajal y de la Cueva named the region the New Kingdom of León, in honor of the Kingdom of León, as Carvajal noted various similarities between both territories, particularly their mountainous terrains. Following Mexican independence, the name was shortened to Nuevo León.

Prior to European colonization, there was no established nation-state. Historians estimate that there were about 250 distinct indigenous nomad groups living in the state's territory, collectively known to the Spaniards as chicimecas. Archaeological remains, such as cave paintings and carved stones, enabled historians to identify four main indigenous groups that inhabited the state: the Coahuiltecans to the west, Alazapas to the north, the "Borrados" to the east, and the Guachichiles to the south.

Like numerous groups across Aridoamerica, the indigenous peoples of Nuevo León were constantly on the move in search for food. Predominantly reliant on hunting and gathering, many peoples traveled in small bands, establishing temporary settlements known as rancherías, which typically housed one or two families. These settlements consisted of semispherical huts constructed from interwoven branches and thatched roofs. Those situated near rivers, such as the Salinas river, or in regions with more temperate climates, like areas near or within the Sierra Madre Oriental mountain range, had access to fishing and limited agriculture.

Due to their nomadic lifestyle, the communities never laid claim to land permanently, and they did not develop political hierarchies similar to the ones found in Mesoamerican societies. Consequently, governance within these tribes was absent, reflecting a decentralized social structure.

In 1535, Alvaro Núñez Cabeza de Vaca led one of the first expeditions into Nuevo León territory. Colonization attempts began in 1577 under Alberto del Canto, who founded Santa Lucía in present-day Monterrey. However, these efforts failed due to indigenous raids, who were labeled as Indios Bárbaros by the colonizers. In 1579, Luis Carvajal y de la Cueva, a member of del Canto's expedition, returned to Spain and negotiated with King Philip II to establish a new territory in northern New Spain. He returned to the territory in 1580 and founded the New Kingdom of León in 1582, with its capital, San Luis Rey de Francia, established where Santa Lucía once stood, marking Monterrey's second founding. However, colonization efforts failed once again in 1588, when Carvajal was reported to the Inquisition, accused of being a descendant of New Christians. Since then, the region remained mostly uninhabited by the Spaniards.