Lake Isabella also called Isabella Lake, is a reservoir in Kern County, California, United States created by the earthen Isabella Dam. At 11,000 acres (4,500 ha), it is one of the larger reservoirs in California. Lake Isabella is located about 40 miles (64 km) northeast of Bakersfield, and is the main water supply for that city. It was formed in 1953 when the U.S. Army Corps of Engineers dammed the Kern River at the junction of its two forks. The area is in the southern end of the Sierra Nevada range and the lake itself is located in low mountains at an elevation of approximately 2,500 ft (760 m) where summer temperatures reach over 100 °F (38 °C) but low enough to avoid winter snows on the surrounding ridges. The former towns of Isabella and Kernville were flooded when the reservoir was created.

Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield.