Los Berros (Spanish for The Watercresses) is a census-designated place in San Luis Obispo County, California. Los Berros sits at an elevation of . The 2020 United States census reported Los Berros's population was 623.
According to the United States Census Bureau, the CDP covers an area of 2.5 square miles (6.5 km<sup>2</sup>), all of it land.
Los Berros first appeared as a census designated place in the 2010 U.S. census.
The 2020 United States census reported that Los Berros had a population of 623. The population density was . The racial makeup of Los Berros was 441 (70.8%) White, 7 (1.1%) African American, 3 (0.5%) Native American, 16 (2.6%) Asian, 0 (0.0%) Pacific Islander, 44 (7.1%) from other races, and 112 (18.0%) from two or more races. Hispanic or Latino of any race were 141 persons (22.6%).
The census reported that 614 people (98.6% of the population) lived in households, 9 (1.4%) lived in non-institutionalized group quarters, and no one was institutionalized.
There were 217 households, out of which 61 (28.1%) had children under the age of 18 living in them, 153 (70.5%) were married-couple households, 3 (1.4%) were cohabiting couple households, 31 (14.3%) had a female householder with no partner present, and 30 (13.8%) had a male householder with no partner present. 35 households (16.1%) were one person, and 20 (9.2%) were one person aged 65 or older. The average household size was 2.83. There were 178 families (82.0% of all households).
The age distribution was 125 people (20.1%) under the age of 18, 64 people (10.3%) aged 18 to 24, 131 people (21.0%) aged 25 to 44, 168 people (27.0%) aged 45 to 64, and 135 people (21.7%) who were 65years of age or older. The median age was 44.5years. For every 100 females, there were 105.6 males.
There were 235 housing units at an average density of , of which 217 (92.3%) were occupied. Of these, 161 (74.2%) were owner-occupied, and 56 (25.8%) were occupied by renters.
It is in the Lucia Mar Unified School District.