Mountainside, NJ Demographics

A map of Mountainside's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	5,029	5,498	71.3%	78.3%
Hispanic	931	667	13.2%	9.5%
Asian	804	466	11.4%	6.6%
Black	155	134	2.2%	1.9%
Multiracial	126	203	1.8%	2.9%
Native American/Other	4	52	0.1%	0.7%

Mountainside, New Jersey has an estimated population of 7,049, a less than 1% change from the 7,020 recorded in the 2020 Census. The population is 71.3% White, 13.2% Hispanic, 11.4% Asian, 2.2% Black, 1.8% Multiracial, and 0.1% Native American/Other. This demographic dot map shows the population of Mountainside, with one dot drawn for each person counted by the Census, color-coded by race.

Mountainside has become considerably more racially diverse since the 2020 Census. It is considerably less diverse than New Jersey overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Mountainside, that probability was 37.2% in 2020 and 46.0% in the most recent ACS estimates.

Mountainside is ranked the 230th most populous place in New Jersey, out of 700 places. This ranking is based on the Census definition of a place, which includes incorporated places like cities, towns, and villages, as well as unincorporated census-designated places (CDPs). Mountainside was ranked the 230th most populous place in the 2020 Census.

Mountainside's White Population

5,029 residents of Mountainside, or 71.3% of the population, identify as White. The share of White residents in Mountainside is significantly higher than in New Jersey overall, where 50.9% of the population is White. Mountainside ranks 297th statewide in terms of White residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's White population has declined by an estimated 8.5%. White residents' share of Mountainside's population has decreased from 78.3% to 71.3%.

Mountainside is more White than neighboring Summit (67.1% White), Fanwood (69.4% White), New Providence (67.9% White), and Garwood (63.3% White). Mountainside is less White than neighboring Westfield (76.5% White).

Mountainside's Black Population

155 residents of Mountainside, or 2.2% of the population, identify as Black. The share of Black residents in Mountainside is lower than in New Jersey overall, where 12.2% of the population is Black. Mountainside ranks 461st statewide in terms of Black residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's Black population has grown by an estimated 15.7%. Black residents' share of Mountainside's population has remained roughly unchanged at 2.2%.

Mountainside is more Black than neighboring New Providence (1.8% Black), and Garwood (0.3% Black). Mountainside is less Black than neighboring Westfield (2.4% Black), Summit (5.9% Black), and Fanwood (3.9% Black).

Mountainside's Asian Population

804 residents of Mountainside, or 11.4% of the population, identify as Asian. The share of Asian residents in Mountainside is comparable to the share in New Jersey overall, where 10% of the population is Asian. Mountainside ranks 219th statewide in terms of Asian residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's Asian population has grown by an estimated 72.5%. Asian residents' share of Mountainside's population has increased from 6.6% to 11.4%.

Mountainside is more Asian than neighboring Westfield (8.8% Asian), Summit (7.3% Asian), Fanwood (6.9% Asian), and Garwood (4.5% Asian). Mountainside is less Asian than neighboring New Providence (14.8% Asian).

Mountainside's Hispanic Population

931 residents of Mountainside, or 13.2% of the population, identify as Hispanic. The share of Hispanic residents in Mountainside is lower than in New Jersey overall, where 22.5% of the population is Hispanic. Mountainside ranks 345th statewide in terms of Hispanic residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's Hispanic population has grown by an estimated 39.6%. Hispanic residents' share of Mountainside's population has increased from 9.5% to 13.2%.

Mountainside is more Hispanic than neighboring Westfield (8% Hispanic), Summit (13.1% Hispanic), Fanwood (11.2% Hispanic), and New Providence (8.8% Hispanic). Mountainside is less Hispanic than neighboring Garwood (21.2% Hispanic).

Mountainside's Native American/Other Population

4 residents of Mountainside, or 0.1% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Mountainside is comparable to the share in New Jersey overall, where 0.9% of the population is Native American/Other. Mountainside ranks 232nd statewide in terms of Native American/Other residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's Native American/Other population has declined by an estimated 92.3%. Native American/Other residents' share of Mountainside's population has decreased from 0.7% to 0.1%.

Mountainside is less Native American/Other than neighboring Westfield (1.1% Native American/Other), Summit (1.4% Native American/Other), Fanwood (0.6% Native American/Other), New Providence (0.3% Native American/Other), and Garwood (7.7% Native American/Other).

Mountainside's Multiracial Population

126 residents of Mountainside, or 1.8% of the population, identify as Multiracial. The share of Multiracial residents in Mountainside is comparable to the share in New Jersey overall, where 3.5% of the population is Multiracial. Mountainside ranks 417th statewide in terms of Multiracial residents as a share of the population, out of 700 places.

Since the 2020 Census, Mountainside's Multiracial population has declined by an estimated 37.9%. Multiracial residents' share of Mountainside's population has decreased from 2.9% to 1.8%.

Mountainside is less Multiracial than neighboring Westfield (3.2% Multiracial), Summit (5.3% Multiracial), Fanwood (8% Multiracial), New Providence (6.4% Multiracial), and Garwood (3% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.