El Segundo is a city in Los Angeles County, California, United States. Located on Santa Monica Bay, it was incorporated on January 18, 1917, and is part of the South Bay Cities Council of Governments. The population was 16,731 as of the 2020 census, a 0.5% increase from 16,654 in the 2010 census. A significant center of the oil and aerospace industries in Southern California, roughly three quarters of the city's land is dedicated exclusively to industrial and commercial uses, including a Chevron oil refinery which alone takes up more than a quarter of the entire city.

Santa Monica Bay is a bight of the Pacific Ocean in Southern California, United States. Its boundaries are slightly ambiguous, but it is generally considered to be the part of the Pacific within an imaginary line drawn between Point Dume, in Malibu, and the Palos Verdes Peninsula. Its eastern shore forms the western boundary of the Los Angeles Westside and South Bay regions. Although it was fed by the Los Angeles River until the river's catastrophic change of course in 1825, the only stream of any size now flowing into it is Ballona Creek. Smaller waterways draining into the bay include Malibu Creek, Topanga Creek, and Santa Monica Creek.