Rancho Los Nietos was one of the first, and the largest, Spanish land concession in Alta California. Located in present-day Los Angeles County and Orange County, California. Rancho Los Nietos was awarded to Manuel Nieto in 1784. After an appeal by the San Gabriel Mission padres, Rancho Los Nietos was later reduced and Rancho Paso de Bartolo was once again a possession of the mission. The rest of the rancho remained intact until 1834, when Governor Jose Figueroa officially declared the Rancho Los Nietos grant under Mexican rule and ordered its partition into six smaller ranchos.
Today, all parts of the following places are located on what was once Rancho Los Nietos, spanning the cities of Southeast LA and north Orange County: