Lake Abert is a large, shallow, alkali lake in Lake County, Oregon, United States. It is approximately 15 mi (24 km) long and 7 mi (11 km) wide at its widest point. It is located 3 mi (4.8 km) northeast of the small, unincorporated community of Valley Falls, Oregon. The lake was named in honor of Colonel John James Abert by explorer John C. Fremont during his 1843 expedition into Central Oregon. No fish live in the alkaline waters of the lake; however, its dense population of brine shrimp supports a variety of shorebirds. The lake is an important stop on the bird migration route known as the Pacific flyway.

Lake County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 8,160. Its county seat is Lakeview. The county is named after the many lakes found within its boundaries, including Lake Abert, Summer Lake, Hart Lake, and Goose Lake.