The Antelope Valley is a valley primarily located in northern Los Angeles County, California, United States and the southeast portion of Kern County, and constitutes the western tip of the Mojave Desert. It is situated between the Tehachapi, Sierra Pelona, and the San Gabriel Mountains. The valley was named for the pronghorns that roamed there until they were all eliminated in the 1880s, mostly by hunting, or resettled in other areas. The principal cities in the Antelope Valley are Palmdale and Lancaster.

The Antelope Valley comprises the western tip of the Mojave Desert, opening up to the Victor Valley and the Great Basin to the east. Lying north of the San Gabriel Mountains, southeast of the Tehachapis, and east of the Sierra Pelona Mountains, this desert ecosystem spans around 2,200 sq mi (5,698 km²). The valley is bounded by the Garlock and San Andreas fault systems. Precipitation in the surrounding mountain ranges contributes to groundwater recharge.

Much of the Los Angeles County portion of the Antelope Valley is laid out in streets at one-mile intervals. Avenues run east-west and streets run north-south. The grid begins at Avenue A (the Los Angeles-Kern County Line), with each letter avenue (B, C...) one mile apart. From Division Street, north-south streets increase by ten each mile (10th Street West, 20th Street East...). Diagonal streets that do not follow the grid include Sierra Highway, Pearblossom Highway, and Fort Tejon Road.

The Antelope Valley is home to a wide range of plants and animals. This includes hundreds of plants such as the California juniper, Joshua tree, California scrub oak, creosote, and wildflowers, notably the California poppy. Winter brings much-needed rain, which slowly penetrates the area's dry ground, bringing up native grasses and wildflowers. Poppy season depends completely on the precipitation, but a good bloom can be killed off by the unusual weather in the late winter and early spring.

The Antelope Valley gets its name from its history of pronghorn grazing in large numbers. In 1882–85, the valley lost 30,000 head of antelope, almost half of the species for which it was named. Unusually heavy snows in both the mountains and the valley floor drove the antelope toward their normal feeding grounds in the eastern part of the valley. Since they would not cross the railroad tracks, many of them starved to death. The remainder of these pronghorns were hunted for their hides by settlers. Once abundant, they either died off or migrated into the Central Valley. A drought in the early 1900s caused a scarcity in bunch grass, their main food source. Now, the sighting of a pronghorn is rare, although a small number remain in the western portion of the valley.

Common game species in the Antelope Valley include mule deer and mountain quail. Other common species in the Antelope Valley include the golden-mantled ground squirrel, Beechey ground squirrel, red-tailed hawk, Cooper's hawk, Stellar's jay, leopard frog, and rattlesnake.

Human water use in the Antelope Valley depends mainly on pumping of groundwater from the valley's aquifers and on importing additional water from the California Aqueduct. Long-term groundwater pumping has lowered the water table, thereby increasing pumping lifts, reducing well efficiency, and causing land subsidence.

While aqueducts supply additional water that meets increasing human demand for agricultural, industrial, and domestic uses, diversion of water from the Sacramento-San Joaquin River Delta in northern California has caused and causes adverse environmental and social effects in the delta: