2000
#15,364
National surname rank
Recorded bearers 1,754
First available Census row
Per 100,000 0.65
Rare Last name
Diem
A surname likely derived from the Vietnamese word "diem" meaning destiny or fate.
According to the 2020 US Census Bureau surname tables, roughly 2,100 Americans carry the last name Diem. That puts it at #15,422 in the national surname ranking, appearing at a frequency of 0.61 per 100,000 people (about 1 in 163,216 residents).
This page is the full Name Census profile for the Diem surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
2.1K
1 in 163,216
Census rank
#15,422
2020 decennial data
Per 100,000
0.6
Frequency rate
Recorded bearers
1.8K
rare in the US
Popularity narrative
The Census Bureau recorded 1,831 bearers of the surname Diem in its 2020 decennial surname file. At a rate of 0.61 per 100,000 residents, it holds the 15422nd position in the national surname ranking.
Among Census respondents with the surname Diem, the largest self-reported group is White at 90.1%. The next largest groups are Two or More Races (3.3%) and Asian/Pacific Islander (3.0%).
Origin
Meaning and origin of Diem
The surname DIEM is derived from the Latin word "dies" meaning "day". It has its origins in ancient Rome, where it may have been used as a name or nickname for someone who was active or cheerful during the daytime.
The name DIEM can be found in various historical records throughout Europe, particularly in regions that were part of the Roman Empire. One of the earliest recorded instances is in the Codex Diplomaticus, a collection of medieval charters and documents from Germany, where a knight named Theodericus Diem is mentioned in the year 1162.
In England, the surname DIEM appears in the Rotuli Hundredorum, a census taken in 1273, where a John Diem is listed as a resident of the county of Oxfordshire. The name is also found in the Pipe Rolls, a series of financial records from the Exchequer of England, dating back to the 12th century.
During the Renaissance period, the name DIEM gained some prominence in Italy. Notable individuals with this surname include Gerolamo Diem (1508-1575), a Venetian painter and engraver, and Giovanni Battista Diem (1590-1668), an Italian composer and organist from Rome.
In France, the DIEM surname can be traced back to the 16th century. One of the earliest recorded instances is Jean Diem (1535-1611), a French Protestant theologian and author from Normandy.
Another notable figure with the DIEM surname is Johann Konrad Diem (1647-1703), a German philosopher and mathematician who was a professor at the University of Giessen in Hesse.
The DIEM name has also been present in other parts of Europe, including the Netherlands, where Pieter Diem (1745-1815) was a Dutch painter and engraver from Rotterdam.
Overall, the surname DIEM has a rich history spanning across various European countries, with its origins rooted in the Latin language and ancient Roman culture. While not among the most common surnames, it has been carried by several individuals of note throughout the centuries.
Demographics
Ancestry and ethnicity for Diem
Among Census respondents with the surname Diem, the largest self-reported group is White at 90.1%. The next largest groups are Two or More Races (3.3%) and Asian/Pacific Islander (3.0%).
The bar chart below shows how Diem bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Diem surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.1% · 1,650
- Two or more races3.3% · 60
- Asian and Pacific Islander3.0% · 55
- Hispanic or Latino2.9% · 53
- Black or African American0.6% · 11
- American Indian and Alaska Native0.1% · 2
Timeline
Historical Census data for Diem
Diem appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#16,284
National surname rank
Recorded bearers 1,771
+17 bearers (+1.0%)
Per 100,000 0.60
Rank movement Down 920 places
2020
#15,422
National surname rank
Recorded bearers 1,831
+60 bearers (+3.4%)
Per 100,000 0.61
Rank movement Up 862 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #15,364 | 1,754 | 0.65 | First available Census row | First available Census row |
| 2010 | #16,284 | 1,771 | 0.60 | +17 bearers (+1.0%) | Down 920 places |
| 2020 | #15,422 | 1,831 | 0.61 | +60 bearers (+3.4%) | Up 862 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Diem surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #16,284 | #15,422 | 5.3% |
| Count | 1,771 | 1,831 | 3.4% |
| Per 100K | 0.60 | 0.61 | 2.1% |
Between the 2010 and 2020 Census, the number of Diem bearers went from 1,771 to 1,831 (+3.4% change). The surname moved up 862 positions in the national ranking, going from #16,284 to #15,422.
FAQ
Diem surname: questions and answers
How many people in the U.S. have the surname Diem?
Name Census estimates that about 2,100 living Americans carry the surname Diem. Using the current population baseline, that works out to roughly 1 in 163,216 residents.
How common is Diem?
Diem ranks #15,422 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.61 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 1,831 people with the surname Diem. That is different from the site's living-bearer estimate (2,100), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.61 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.61 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Diem.
Has Diem become more or less common over time?
Between 2010 and 2020, the surname Diem went from 1,771 recorded bearers to 1,831. That is an increase of 60 (+3.4%). In the national ranking it rose from #16,284 to #15,422.
What does the Census say about the background of Diem?
Among Census respondents with the surname Diem, the largest self-reported group is White at 90.1%. The next largest groups are Two or More Races (3.3%) and Asian/Pacific Islander (3.0%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Diem in the 2020 Census, accounting for 90.1% (1,650 people in the source table).
What is the full ancestry breakdown?
Diem appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.1%), Two or More Races (3.3%), Asian/Pacific Islander (3.0%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Diem (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Diem mean?
A surname likely derived from the Vietnamese word "diem" meaning destiny or fate. The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Diem (0.61 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How common is the surname Diem?
Our sister site HowManyOfMe.org answers how common the surname Diem is at a glance, with the living-bearer count up front.