2000
#5,557
National surname rank
Recorded bearers 5,739
First available Census row
Per 100,000 2.13
Rare Last name
Dilley
A locational surname derived from a place name meaning "dell" or "small valley" combined with the suffix "-ley."
According to the 2020 US Census Bureau surname tables, roughly 6,122 Americans carry the last name Dilley. That puts it at #6,152 in the national surname ranking, appearing at a frequency of 1.79 per 100,000 people (about 1 in 55,987 residents).
This page is the full Name Census profile for the Dilley 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.
For British records, Name Census UK has a British surname profile for Dilley with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
6.1K
1 in 55,987
Census rank
#6,152
2020 decennial data
Per 100,000
1.8
Frequency rate
Recorded bearers
5.3K
rare in the US
Popularity narrative
The Census Bureau recorded 5,339 bearers of the surname Dilley in its 2020 decennial surname file. At a rate of 1.79 per 100,000 residents, it holds the 6152nd position in the national surname ranking.
Among Census respondents with the surname Dilley, the largest self-reported group is White at 91.4%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.2%).
Origin
Meaning and origin of Dilley
The surname Dilley is of English origin, derived from the Old English word "dill" meaning a valley or hollow. It is thought to have originated as a topographic name, given to someone who lived in a small valley or dell.
Dilley is believed to have originated in the counties of Gloucestershire, Worcestershire, and Shropshire in the West Midlands region of England. The earliest recorded instance of the name is found in the Hundredorum Rolls of 1273, which list a Richard de la Dulle residing in Worcestershire.
The name has undergone various spelling variations over the centuries, including Dilie, Dilly, Dille, Dillie, and Dilli. These variations can be found in various medieval records and documents such as parish registers, tax rolls, and court records.
One notable early bearer of the name was John Dilly, a merchant and alderman of the City of London in the late 16th century. He served as Master of the Worshipful Company of Grocers in 1594 and was involved in the city's governance during a turbulent period of English history.
Another individual of historical significance was Sir Samuel Dilley (1617-1688), an English lawyer and judge who served as Lord Chief Baron of the Exchequer. He was renowned for his legal expertise and played a crucial role in shaping English common law during the tumultuous years following the English Civil War.
In the 18th century, James Dilley (1746-1822) was a prominent English architect who designed several notable buildings in London, including the Royal Circus in Blackfriars and the Church of St. Paul in Covent Garden.
Moving into the 19th century, we find Mary Dilley (1825-1903), a British author and educator who wrote several books on the education of young children. Her works were widely influential in promoting progressive teaching methods during the Victorian era.
Lastly, one cannot discuss the Dilley surname without mentioning Sir Charles Wentworth Dilley (1889-1962), a British Army officer and military historian who served in both World Wars. His seminal work, "The Triumph of the English Language," is considered a landmark in the study of military linguistics.
While many variations of the name exist, the core Dilley surname has endured for centuries, reflecting its deep-rooted English heritage and the numerous notable individuals who have borne this distinctive surname throughout history.
Demographics
Ancestry and ethnicity for Dilley
Among Census respondents with the surname Dilley, the largest self-reported group is White at 91.4%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.2%).
The bar chart below shows how Dilley 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 Dilley surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.4% · 4,881
- Hispanic or Latino3.8% · 205
- Two or more races3.2% · 169
- Asian and Pacific Islander0.6% · 30
- Black or African American0.5% · 28
- American Indian and Alaska Native0.5% · 26
Timeline
Historical Census data for Dilley
Dilley 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
#6,036
National surname rank
Recorded bearers 5,692
-47 bearers (-0.8%)
Per 100,000 1.93
Rank movement Down 479 places
2020
#6,152
National surname rank
Recorded bearers 5,339
-353 bearers (-6.2%)
Per 100,000 1.79
Rank movement Down 116 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #5,557 | 5,739 | 2.13 | First available Census row | First available Census row |
| 2010 | #6,036 | 5,692 | 1.93 | -47 bearers (-0.8%) | Down 479 places |
| 2020 | #6,152 | 5,339 | 1.79 | -353 bearers (-6.2%) | Down 116 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 Dilley 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 | #6,036 | #6,152 | -1.9% |
| Count | 5,692 | 5,339 | -6.2% |
| Per 100K | 1.93 | 1.79 | -7.4% |
Between the 2010 and 2020 Census, the number of Dilley bearers went from 5,692 to 5,339 (-6.2% change). The surname moved down 116 positions in the national ranking, going from #6,036 to #6,152.
FAQ
Dilley surname: questions and answers
How many people in the U.S. have the surname Dilley?
Name Census estimates that about 6,122 living Americans carry the surname Dilley. Using the current population baseline, that works out to roughly 1 in 55,987 residents.
How common is Dilley?
Dilley ranks #6,152 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.79 per 100,000 residents, which is about 2 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 5,339 people with the surname Dilley. That is different from the site's living-bearer estimate (6,122), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.79 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.79 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 2 of them to have the surname Dilley.
Has Dilley become more or less common over time?
Between 2010 and 2020, the surname Dilley went from 5,692 recorded bearers to 5,339. That is a decrease of 353 (-6.2%). In the national ranking it fell from #6,036 to #6,152.
What does the Census say about the background of Dilley?
Among Census respondents with the surname Dilley, the largest self-reported group is White at 91.4%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.2%). 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 Dilley in the 2020 Census, accounting for 91.4% (4,881 people in the source table).
What is the full ancestry breakdown?
Dilley appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.4%), Hispanic (3.8%), Two or More Races (3.2%). 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 Dilley (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 Dilley mean?
A locational surname derived from a place name meaning "dell" or "small valley" combined with the suffix "-ley." 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 Dilley (1.79 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 Dilley?
Want to know how many people have the last name Dilley? HowManyOfMe.org, our sister site, puts the living-bearer count front and centre.