Carlsbad Caverns National Park is a national park of the United States in the Guadalupe Mountains of southeastern New Mexico. The primary attraction of the park is the show cave Carlsbad Cavern. Visitors can hike in on their own via the natural entrance or take an elevator from the visitor center.

The park entrance is located on US Highway 62/180, approximately 18 miles (29 km) southwest of Carlsbad, New Mexico. The park has two entries on the National Register of Historic Places: The Caverns Historic District and the Rattlesnake Springs Historic District. Approximately two-thirds of the park has been set aside as a wilderness area, helping to ensure that no future changes will be made to the habitat.

Carlsbad Caverns includes a large limestone chamber, named simply the Big Room, which is almost 4,000 ft (1,220 m) long, 625 ft (191 m) wide, and 255 ft (78 m) high at its highest point. The Big Room is the largest chamber in North America and the 32nd largest in the world.

Carlsbad Caverns was established as a national park in 1930 and was recognized as a World Heritage Site in 1995. According to The Travel, it is renowned globally for being "one of the most accessible and best-preserved cave complexes in the world".

An estimated 250 million years ago, the area surrounding Carlsbad Caverns National Park served as the coastline for an inland sea. Present in the sea was a plethora of marine life, whose remains formed a reef. Unlike modern reef growths, the Permian reef contained bryozoans, sponges, and other microorganisms. After the Permian Period, most of the water evaporated and the reef was buried by evaporites and other sediments. Tectonic movement occurred during the late Cenozoic, uplifting the reef above ground. Susceptible to erosion, water sculpted the Guadalupe Mountain region into its present-day state.

Carlsbad Caverns National Park is situated in a bed of limestone above groundwater level. During cavern development, it was within the groundwater zone. Deep below the limestones are petroleum reserves (part of the Mid-Continent Oil Field). At a time near the end of the Cenozoic, hydrogen sulfide (H₂S) began to seep upwards from the petroleum into the groundwater. The combination of hydrogen sulfide and oxygen from the water formed sulfuric acid: H₂S + 2O₂ → H₂SO₄. The sulfuric acid then continued upward, aggressively dissolving the limestone deposits to form caverns. The presence of gypsum within the cave is a confirmation of the occurrence of this process, as it is a byproduct of the reaction between sulfuric acid and limestone.

Once the acidic groundwater drained from the caverns, speleothems began to be deposited within the cavern. Erosion above ground created the natural entrance to the Carlsbad Caverns within the last million years. Exposure to the surface has allowed for the influx of air into the cavern. Rainwater and snowmelt percolating downward into the ground pick up carbon dioxide; once this water reaches a cavern ceiling, it precipitates and evaporates, leaving behind a small calcium carbonate deposit. Growths from the roof downward formed through this process are known as stalactites. Additionally, water on the floor of the caverns can contain carbonic acid and generate mineral deposits by evaporation. Growths from the floor upward through this process are known as stalagmites. Different formations of speleothems include columns, soda straws, draperies, helictites, and popcorn. Changes in the ambient air temperature and rainfall affect the rate of growth of speleothems, as higher temperatures increase carbon dioxide production rates within the overlying soil. The color of the speleothems is determined by the trace constituents in the minerals of the formation.

According to the Köppen climate classification system, the Carlsbad Caverns Visitor Center has a cool semi-arid climate (BS).