Ogallala is a city in and the county seat of Keith County, Nebraska, United States. The population was 4,737 at the 2010 census. In the days of the Nebraska Territory, the city was a stop on the Pony Express and later along the transcontinental railroad. The Ogallala Aquifer was named after the city.
Ogallala first gained fame as a terminus for cattle drives that traveled from Texas to the Union Pacific railhead located there. These trails are known as the Western or Great Western trails. The Union Pacific Railroad reached Ogallala on May 24, 1867. The city itself was not laid out until 1875 and not incorporated until 1884 The town's name comes from the Oglala Sioux tribe.
Ogallala is located at 41°7′44″N 101°43′10″W (41.128806, -101.719460). According to the United States Census Bureau, the city has a total area of 5.02 square miles (13.00 km2), of which 4.96 square miles (12.85 km2) is land and 0.06 square miles (0.16 km2) is water. Ogallala is in the US Mountain Time Zone (UTC−7/-6).