Inhabited by Native American populations for many centuries, it has also been part of the Imperial Spanish viceroyalty of New Spain, part of Mexico, and a U.S. territory. Among U.S. states, New Mexico has the highest percentage of Hispanics, at 44 percent (2008 estimate), including descendants of Spanish colonists and recent immigrants from Latin America. It also has the third-highest percentage of Native Americans, after Alaska and Oklahoma, and the fifth-highest total number of Native Americans after California, Oklahoma, Arizona, and Texas. The tribes in the state consist of mostly Navajo and Pueblo peoples. As a result, the demographics and culture of the state are unique for their strong Hispanic, Mexican, and Native American influences. The flag of New Mexico is represented by the red and gold colours, which represent Spain, as well as the Zia symbol, an ancient Native American symbol for the sun.

The state's total area is 121,412 square miles (314,460 km2). The eastern border of New Mexico lies along 103° W longitude with the state of Oklahoma, and three miles (5 km) west of 103.5° W longitude with Texas. On the southern border, Texas makes up the eastern two-thirds, while the Mexican states of Chihuahua and Sonora make up the western third, with Chihuahua making up about 90% of that. The western border with Arizona runs along the 109° 03' W longitude. The southwestern corner of the state is known as the Bootheel. The 37° N latitude parallel forms the northern boundary with Colorado. The states New Mexico, Colorado, Arizona, and Utah come together at the Four Corners in the northwestern corner of New Mexico. New Mexico, although a large state, has little water. Its surface water area is about 250 square miles (650 km2).

The New Mexican landscape ranges from wide, rose-colored deserts to broken mesas to high, snow-capped peaks. Despite New Mexico's arid image, heavily forested mountain wildernesses cover a significant portion of the state, especially towards the north. The Sangre de Cristo Mountains, the southernmost part of the Rocky Mountains, run roughly north-south along the east side of the Rio Grande in the rugged, pastoral north. The most important of New Mexico's rivers are the Rio Grande, Pecos, Canadian, San Juan, and Gila. The Rio Grande is the eighth longest river in the U.S.

The U.S. government protects millions of acres of New Mexico as national forests including:

Areas managed by the National Park Service include:

Visitors also frequent the surviving native pueblos of New Mexico. Tourists visiting these sites bring significant monies to the state. Other areas of geographical and scenic interest include Kasha-Katuwe Tent Rocks National Monument and the Valles Caldera National Preserve. The Gila Wilderness lies in the southwest of the state.

The climate of New Mexico is highly arid and its territory is mostly covered by mountains, high plains, and desert. New Mexico's average precipitation rate is 9 inches (230 mm) a year. The average annual temperatures can range from 64 °F (18 °C) in the southeast to less than 40 °F (4 °C) in the northern mountains. During the summer months, daytime temperatures can often exceed 100 °F (38 °C) at elevations below 5,000 feet, the average high temperature in July ranges from 97 °F (36 °C) at the lower elevations to the upper 70s (°F, up to 26°C) at the higher elevations. The highest temperature recorded in New Mexico was 116 °F (47 °C) at Artesia on June 29, 1918.

New Mexico offers habitat for occurrence of many plant and animal species, with emphasis upon many desert areas and large amounts of pinon-juniper woodland. Creosote bush, mesquite, cacti, yucca, and desert grasses, including black grama, purple three-awn, tobosa, and burrograss, cover the broad, semiarid plains that cover the southern portion of the state. Native birds include the Road-runner, Geococcyx californianus and Wild turkey, Meleagris gallopavo subspecies mexicana.

The first known inhabitants of New Mexico were members of the Clovis culture of Paleo-Indians.:19 Later inhabitants include Native Americans of the Mogollon and the Anasazi cultures.:52 By the time of European contact in the 16th century, the region was settled by the villages of the Pueblo peoples and groups of Navajo, Apache and Ute.:6,48

Francisco Vázquez de Coronado assembled an enormous expedition at Compostela in 1540–1542 to explore and find the mystical Seven Golden Cities of Cibola as described by Fray Marcos de Niza.:19–24 The name Nuevo México was first used by a seeker of gold mines named Francisco de Ibarra who explored far to the north of Mexico in 1563 and reported his findings as being in "a New Mexico". Juan de Oñate officially established the name when he was appointed the first governor of the new Province of New Mexico in 1598.:36–37 In 1598 he founded the San Juan de los Caballeros colony, the first permanent European settlement in the future state of New Mexico, on the Rio Grande near Ohkay Owingeh Pueblo.:37 Oñate extended El Camino Real de Tierra Adentro, "Royal Road of the Interior," by 700 miles (1,100 km) from Santa Bárbara, Chihuahua to his remote colony.:49