East Nicolaus is a census-designated place (CDP) in Sutter County, California. East Nicolaus sits at an elevation of . The 2020 United States census reported East Nicolaus's population was 223. It is home to East Nicolaus High School (ENHS), a public school that serves grades nine through twelve.
According to the United States Census Bureau, the CDP covers an area of 4.6 square miles (11.9 km<sup>2</sup>), all of it land.
The 2020 United States census reported that East Nicolaus had a population of 223. The population density was . The racial makeup of East Nicolaus was 139 (62.3%) White, 0 (0.0%) African American, 8 (3.6%) Native American, 7 (3.1%) Asian, 2 (0.9%) Pacific Islander, 27 (12.1%) from other races, and 40 (17.9%) from two or more races. Hispanic or Latino of any race were 53 persons (23.8%).
The whole population lived in households. There were 85 households, out of which 21 (24.7%) had children under the age of 18 living in them, 40 (47.1%) were married-couple households, 4 (4.7%) were cohabiting couple households, 20 (23.5%) had a female householder with no partner present, and 21 (24.7%) had a male householder with no partner present. 25 households (29.4%) were one person, and 18 (21.2%) were one person aged 65 or older. The average household size was 2.62. There were 56 families (65.9% of all households).
The age distribution was 33 people (14.8%) under the age of 18, 17 people (7.6%) aged 18 to 24, 50 people (22.4%) aged 25 to 44, 61 people (27.4%) aged 45 to 64, and 62 people (27.8%) who were 65years of age or older. The median age was 48.3years. For every 100 females, there were 93.9 males.
There were 98 housing units at an average density of , of which 85 (86.7%) were occupied. Of these, 64 (75.3%) were owner-occupied, and 21 (24.7%) were occupied by renters.