Demographics of Diamond Bar city, California

Diamond Bar city, California had 51,884 people on July 1, 2025, by the Census Bureau’s estimate: −3,122 since July 2020. Age, income, poverty, housing and origin below come from the survey, averaged over 2020–2024, each with its margin of error.

Diamond Bar city, in four figures

51,884
Population: July 1, 2025, Vintage 2025 estimate. The survey’s 2020–⁠2024 figure is 53,355 ±61.; −5.7%
Change since July 2020: −3,122 people.; 45.7 ±0.9
Median age: ACS 2020–⁠2024.; $108,281 ±$6,624
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. The Bureau publishes no births, deaths or migration for a place, so the change is the difference between one July estimate and the next.

Diamond Bar city, California's population shrank 5.7% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Diamond Bar city, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

Source: The Census Bureau

About this chart

The figures

Diamond Bar city, California's population shrank 5.7% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Diamond Bar city, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	55,006	100.0	100.0
2021	53,847	97.9	100.2
2022	53,036	96.4	100.7
2023	52,539	95.5	101.6
2024	52,288	95.1	102.5
2025	51,884	94.3	103.1

Population of Diamond Bar city, California on July 1 of each year, Vintage 2025
July 1	Population	Change
2020	55,006	—
2021	53,847	−1,159
2022	53,036	−811
2023	52,539	−497
2024	52,288	−251
2025	51,884	−404

Age, 2020–2024

The median age is 45.7 ±0.9: for men 45.5 ±1.2 and for women 45.8 ±1.6. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Diamond Bar city by age, ACS 2020–2024
Age	People	Share	California	United States
Under 5	1,896 ±392	3.6% ±0.7	5.5% ±<0.1	5.6% ±<0.1
5 to 17	8,230 ±684	15.4% ±1.3	16.5% ±<0.1	16.3% ±<0.1
18 to 24	3,453 ±439	6.5% ±0.8	9.1% ±<0.1	9.1% ±<0.1
25 to 44	12,428 ±856	23.3% ±1.6	28.7% ±<0.1	26.9% ±<0.1
45 to 64	16,131 ±903	30.2% ±1.7	24.6% ±<0.1	24.8% ±<0.1
65 and over	11,217 ±806	21.0% ±1.5	15.7% ±<0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $108,281 ±$6,624, and income per person $47,945 ±$2,556, in 2024 dollars. The median is $99,122 ±$310 in California and $80,734 ±$166 in the United States.

Households by income

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Households in Diamond Bar city by income, ACS 2020–2024
Household income	Households	Share	California	United States
Under $25,000	2,034 ±416	11.3% ±2.3	12.5% ±0.1	14.6% ±<0.1
$25,000 to $49,999	2,386 ±457	13.3% ±2.5	13.3% ±0.1	16.7% ±<0.1
$50,000 to $74,999	2,090 ±311	11.6% ±1.7	13.0% ±0.1	15.5% ±<0.1
$75,000 to $99,999	1,874 ±265	10.4% ±1.4	11.6% ±0.1	12.6% ±<0.1
$100,000 to $149,999	3,351 ±376	18.6% ±2.0	17.8% ±0.1	17.5% ±<0.1
$150,000 to $199,999	2,308 ±303	12.8% ±1.6	11.3% ±0.1	9.6% ±<0.1
$200,000 or more	3,962 ±417	22.0% ±2.2	20.5% ±0.1	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Diamond Bar city by age, ACS 2020–2024
Age	Below poverty	Rate	California	United States
All ages	5,342 ±1,188	10.0% ±2.2	12.0% ±0.1	12.5% ±0.1
Under 18	1,358 ±430	13.6% ±4.1	15.0% ±0.1	16.1% ±0.1
18 to 59	2,345 ±592	8.3% ±2.1	11.0% ±0.1	11.6% ±0.1
60 and over	1,639 ±525	10.8% ±3.4	11.5% ±0.1	11.0% ±<0.1

Housing, 2020–2024

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Housing in Diamond Bar city, ACS 2020–2024
Measure	Diamond Bar city	California	United States
Housing units	18,969 ±566	14,644,735 ±1,665	143,775,355 ±10,234
Occupied	94.9% ±0.8	92.5% ±0.1	89.9% ±0.1
Vacant	5.1% ±1.3	7.5% ±0.1	10.1% ±0.1
Owner occupied	77.3% ±2.8	55.9% ±0.3	65.2% ±0.3
Renter occupied	22.7% ±2.2	44.1% ±0.2	34.8% ±0.1
Median home value	$902,200 ±$17,619	$734,700 ±$1,307	$332,700 ±$236
Median gross rent	$2,521 ±$121	$2,036 ±$5	$1,413 ±$2
Median year built	1980 ±1	1976 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Diamond Bar city by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	California	United States
Hispanic or Latino	9,291 ±992	17.4% ±1.9	40.2% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	6,276 ±705	11.8% ±1.3	33.8% ±<0.1	57.4% ±<0.1
Black alone, not Hispanic	1,603 ±539	3.0% ±1.0	5.2% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	33,316 ±1,547	62.4% ±2.9	15.3% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	69 to 511	0.1% to 1.0%	0.3% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	36 to 274	0.1% to 0.5%	0.3% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	0 to 584	0% to 1.1%	0.6% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	2,156 ±575	4.0% ±1.1	4.4% ±<0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Diamond Bar city by place of birth and citizenship, ACS 2020–2024
Born	People	Share	California	United States
Born in the state	23,555 ±1,241	44.1% ±2.3	56.5% ±0.1	57.3% ±<0.1
Born in another state	3,874 ±574	7.3% ±1.1	15.0% ±0.1	26.9% ±<0.1
Born a citizen outside the states	695 ±227	1.3% ±0.4	1.5% ±<0.1	1.7% ±<0.1
Born abroad	25,231 ±1,203	47.3% ±2.3	27.0% ±0.1	14.1% ±<0.1
Naturalized citizens	17,653 ±1,159	33.1% ±2.2	14.7% ±0.1	7.4% ±<0.1
Not citizens	7,578 ±981	14.2% ±1.8	12.3% ±0.1	6.8% ±<0.1

Diamond Bar city among the places of California

173rd of 661 places of 5,000 or more by the survey’s 2020–2024 count. Every one is listed on the California page.

Places of California near Diamond Bar city in population, ACS 2020–2024
Place	ACS 2020–⁠2024
Arcadia city	55,170 ±64
West Sacramento city	54,927 ±73
Yucaipa city	54,421 ±90
Hacienda Heights CDP	54,291 ±1,942
Colton city	53,772 ±47
Diamond Bar city	53,355 ±61
Huntington Park city	53,108 ±51
Lincoln city	52,956 ±89
Placentia city	52,826 ±59
Novato city	52,546 ±71
Cathedral City city	52,267 ±75

Elsewhere on the site

Reported crime in Diamond Bar city, California

Rankings this appears in

No. 7 Places in California by foreign-born share
No. 38 Places in California by median age
No. 41 Places by foreign-born share
No. 55 Places in California by median rent
No. 57 Places in California by homeownership rate
No. 112 Places by median rent

Sources

Census Bureau population estimates — incorporated places and New England towns — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Compiled automatically from Census Bureau population estimates — incorporated places and New England towns and American Community Survey 5-year estimates — table-based Summary File by a checked SQL query · Editor: Kian O'Connor · How this site is built

Data retrieved September 25, 2026