Grand Teton National Park is a United States National Park located in northwestern Wyoming, south of Yellowstone National Park. The park is named after the Grand Teton, which, at 13,770 feet (4,197 m), is the tallest mountain in the Teton Range.

The name “Tetons” originally was intended to describe several hills near the town of Arco, Idaho. They were named by a French trapper who thought that they resembled the female body. (Ergo tétons, the French word for “nipples” or “teats”.) Many years later the name was mistakenly applied to the mountains of present day Grand Teton National Park due to the poor map-making and map-reading standards of the time.

Grand Teton National Park was established on February 26, 1929. The park covers 484 mi² (1,255 km²) of land and water.

Part of the Rocky Mountains, the north-south-trending Teton Range rises from the floor of Jackson Hole without any foothills along a 65 km long by 11 to 15 km wide active fault-block mountain front system. In addition to 4,197 m high Grand Teton, another eight peaks are over 3,660 m above sea level. Seven of these peaks between Avalanche and Cascade canyons make up the often-photographed Cathedral Group.