Rancho Los Alamitos takes its name from an 1834 Mexican partition of the 1784 Rancho Los Nietos, a Spanish concession, covering an area in present-day California's southwestern Los Angeles County and northwestern Orange County. Los Alamitos means the Little Cottonwoods or Poplars in Spanish, after the native Fremont Cottonwood trees there.
Rancho Los Alamitos originally included much of the area of present-day eastern Long Beach, all of Los Alamitos and Rossmoor, and most of Seal Beach, Cypress, Stanton and Garden Grove. It is also sometimes referred to as Bixby Ranch, after its last private owners. The early 19th century adobe ranch house still stands today, housing a museum which presents the history of the area.