2000
#8,217
National surname rank
Recorded bearers 3,713
First available Census row
Per 100,000 1.38
Rare Last name
Oday
A variant of the Irish surname O'Day, derived from the Gaelic "Ó Deághaidh," meaning "descendant of Deaghadh."
According to the 2020 US Census Bureau surname tables, roughly 4,194 Americans carry the last name Oday. That puts it at #8,619 in the national surname ranking, appearing at a frequency of 1.22 per 100,000 people (about 1 in 81,725 residents).
This page is the full Name Census profile for the Oday 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 Oday with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
4.2K
1 in 81,725
Census rank
#8,619
2020 decennial data
Per 100,000
1.2
Frequency rate
Recorded bearers
3.7K
rare in the US
Popularity narrative
The Census Bureau recorded 3,657 bearers of the surname Oday in its 2020 decennial surname file. At a rate of 1.22 per 100,000 residents, it holds the 8619th position in the national surname ranking.
Among Census respondents with the surname Oday, the largest self-reported group is White at 88.4%. The next largest groups are Two or More Races (3.6%) and Hispanic (3.5%).
Origin
Meaning and origin of Oday
The surname ODAY originated in Ireland, with the earliest recorded examples dating back to the 12th century. It is an anglicized version of the Irish Gaelic name "O'Dáith," which means "descendant of Dáith." The name Dáith is thought to be derived from the Old Irish word "dáth," meaning "poet" or "learned person."
One of the earliest recorded instances of the name ODAY can be found in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the 17th century. The annals mention an individual named "Domhnall O'Dáith" who lived in the 13th century and was a member of the bardic family of O'Dáith in County Westmeath, Ireland.
In the 16th century, the name ODAY appeared in various Irish records, such as the Fiants of the Tudor Sovereigns, which were legal documents issued by the English Crown in Ireland. One notable individual from this time was Edmond ODAY, who was granted lands in County Cavan in 1584.
During the 17th and 18th centuries, the ODAY surname was found in various parts of Ireland, particularly in Counties Westmeath, Cavan, and Longford. One prominent figure was Patrick ODAY (1670-1747), a Catholic priest who served as the Archbishop of Armagh from 1726 until his death.
In the 19th century, the name ODAY became more widespread, with families bearing the surname found in various regions of Ireland and beyond. John ODAY (1805-1877) was a notable Irish politician and journalist who served as a Member of Parliament for County Cavan in the mid-1800s.
Another individual of note was Thomas ODAY (1848-1922), an Irish-born American politician who served as the Mayor of San Francisco from 1895 to 1897. He played a significant role in the city's reconstruction efforts following the devastating earthquake and fire of 1906.
Throughout its history, the surname ODAY has undergone various spelling variations, including O'Day, O'Dea, and O'Dee, reflecting the anglicization of the original Irish Gaelic name. While the name has been found in various parts of the world due to Irish emigration, its roots can be traced back to the poetic and learned families of Ireland's ancient bardic tradition.
Demographics
Ancestry and ethnicity for Oday
Among Census respondents with the surname Oday, the largest self-reported group is White at 88.4%. The next largest groups are Two or More Races (3.6%) and Hispanic (3.5%).
The bar chart below shows how Oday 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 Oday surname at the time of the 2020 Census, not any inherent property of the name itself.
- White88.4% · 3,234
- Two or more races3.6% · 132
- Hispanic or Latino3.5% · 127
- Black or African American2.8% · 103
- Asian and Pacific Islander1.3% · 46
- American Indian and Alaska Native0.4% · 15
Timeline
Historical Census data for Oday
Oday 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
#8,878
National surname rank
Recorded bearers 3,688
-25 bearers (-0.7%)
Per 100,000 1.25
Rank movement Down 661 places
2020
#8,619
National surname rank
Recorded bearers 3,657
-31 bearers (-0.8%)
Per 100,000 1.22
Rank movement Up 259 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #8,217 | 3,713 | 1.38 | First available Census row | First available Census row |
| 2010 | #8,878 | 3,688 | 1.25 | -25 bearers (-0.7%) | Down 661 places |
| 2020 | #8,619 | 3,657 | 1.22 | -31 bearers (-0.8%) | Up 259 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 Oday 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 | #8,878 | #8,619 | 2.9% |
| Count | 3,688 | 3,657 | -0.8% |
| Per 100K | 1.25 | 1.22 | -2.1% |
Between the 2010 and 2020 Census, the number of Oday bearers went from 3,688 to 3,657 (-0.8% change). The surname moved up 259 positions in the national ranking, going from #8,878 to #8,619.
FAQ
Oday surname: questions and answers
How many people in the U.S. have the surname Oday?
Name Census estimates that about 4,194 living Americans carry the surname Oday. Using the current population baseline, that works out to roughly 1 in 81,725 residents.
How common is Oday?
Oday ranks #8,619 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.22 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 3,657 people with the surname Oday. That is different from the site's living-bearer estimate (4,194), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.22 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.22 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 Oday.
Has Oday become more or less common over time?
Between 2010 and 2020, the surname Oday went from 3,688 recorded bearers to 3,657. That is a decrease of 31 (-0.8%). In the national ranking it rose from #8,878 to #8,619.
What does the Census say about the background of Oday?
Among Census respondents with the surname Oday, the largest self-reported group is White at 88.4%. The next largest groups are Two or More Races (3.6%) and Hispanic (3.5%). 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 Oday in the 2020 Census, accounting for 88.4% (3,234 people in the source table).
What is the full ancestry breakdown?
Oday appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (88.4%), Two or More Races (3.6%), Hispanic (3.5%). 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 Oday (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 Oday mean?
A variant of the Irish surname O'Day, derived from the Gaelic "Ó Deághaidh," meaning "descendant of Deaghadh." 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 Oday (1.22 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 Oday?
You can see how many people are called Oday on our sister site HowManyOfMe.org — same data roots, lighter UI.