Explore the Family Name Riordan
The meaning of Riordan
Irish (Kerry): shortened form of O’Riordan, an Anglicized form of Gaelic Ó Ríoghbhárdáin ‘descendant of Rióghbhárdán’, a byname composed of the elements ríogh- ‘royal’ + a diminutive of bárd ‘bard, poet’. Some characteristic forenames: Irish Brendan, Liam, Aidan, John Patrick, Siobhan.
Dictionary of American Family Names, 2nd edition, © Oxford University Press, 2022.
How common is the last name Riordan in the United States?
Based on the Decennial U.S. Census, the popularity of the surname Riordan increased slightly between 2000 and 2010. In 2000, it held the rank of 4433 among all surnames, but by 2010, it had risen to the rank of 4515. However, despite this increase in rank, there was a slight decline of -1.85% in its percentage change. The actual count of individuals with the Riordan surname also experienced an increase, growing from 7394 in 2000 to 7848 in 2010 — a rise of 6.14%. Similarly, the proportion per 100k people bearing this surname decreased by -2.92%, moving from 2.74 in 2000 to 2.66 in 2010.
| 2000 | 2010 | Change | |
|---|---|---|---|
| Rank | #4,433 | #4,515 | -1.85% |
| Count | 7,394 | 7,848 | 6.14% |
| Proportion per 100k | 2.74 | 2.66 | -2.92% |
Race and Ethnicity of people with the last name Riordan
When it comes to the ethnic identity associated with the surname Riordan, as per the Decennial U.S. Census data, it appears that most individuals identify as White. In the year 2000, individuals identifying as White made up 96.46% of those with the Riordan surname. By 2010, this percentage had decreased slightly to 94.78%. On the other hand, the proportion of individuals identifying as Black or Asian/Pacific Islander significantly increased during this time period, rising from 0.23% and 0.54% respectively in 2000 to 0.68% and 0.94% in 2010. Individuals who identified as Hispanic also saw a considerable increase from 1.23% in 2000 to 2.08% in 2010. The number of people identifying with two or more races remained static at 1.33%, while those identifying as American Indian and Alaskan Native slightly decreased from 0.22% to 0.20%.
| 2000 | 2010 | Change | |
|---|---|---|---|
| White | 96.46% | 94.78% | -1.74% |
| Hispanic | 1.23% | 2.08% | 69.11% |
| Two or More Races | 1.33% | 1.33% | 0% |
| Asian/Pacific Islander | 0.54% | 0.94% | 74.07% |
| Black | 0.23% | 0.68% | 195.65% |
| American Indian and Alaskan Native | 0.22% | 0.2% | -9.09% |
Riordan ancestry composition
23andMe computes an ancestry breakdown for each customer. People may have ancestry from just one population or they may have ancestry from several populations. The most commonly-observed ancestry found in people with the surname Riordan is British & Irish, which comprises 65.6% of all ancestry found in people with the surname. The next two most common ancestries are French & German (13.4%) and Italian (5.0%). Additional ancestries include Eastern European, Spanish & Portuguese, Scandinavian, Indigenous American, and Greek & Balkan.
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| ANCESTRY BREAKDOWN | COMPOSITION |
|---|---|
| British & Irish | 65.6% |
| French & German | 13.4% |
| Italian | 5.0% |
| Other | 16.0% |
Possible origins of the surname Riordan
Your DNA provides clues about where your recent ancestors may have lived. Having many distant relatives in the same location suggests that you may all share common ancestry there. Locations with many distant relatives can also be places where people have migrated recently, such as large cities. If a large number of individuals who share your surname have distant relatives in a specific area, it could indicate a connection between your surname and that location, stemming from either recent ancestral ties or migration.
Based on 23andMe data, people with last name Riordan have recent ancestry locations in the United Kingdom of Great Britain and Northern Ireland and Ireland.
| RECENT ANCESTRY Location | Percentage |
|---|---|
| Glasgow City, United Kingdom | 87.60% |
| Tyne And Wear, United Kingdom | 87.60% |
| Merseyside, United Kingdom | 87.60% |
| Greater Manchester, United Kingdom | 87.60% |
| Greater London, United Kingdom | 87.60% |
What Riordan haplogroups can tell you
Haplogroups are genetic population groups that share a common ancestor on either your paternal or maternal line. These paternal and maternal haplogroups shed light on your genetic ancestry and help tell the story of your family.
The top paternal haplogroup of people with the surname Riordan is R-CTS3087, which is predominantly found among people with European ancestry. Haplogroup R-CTS3087 is descended from haplogroup R-M343. Other common haplogroups include R-L21 and R-Z255, which are predominantly found among people with European and European ancestry. Other surnames with similar common haplogroups are: Reardon, Spain, Enright, Gavin, Crotty, Coggins, Scanlan, Hayman, Anglin, Garvey.
The most common maternal haplogroups of people with Riordan surname are: H1, K1a, H. These most commonly trace back to individuals of European ancestry.
Paternal Haplogroup Origins R-M343Your maternal lineage may be linked to Marie Antoinette
Because it is so dominant in the general European population, haplogroup H also appears quite frequently in the continent's royal houses. Marie Antoinette, an Austrian Hapsburg who married into the French royal family, inherited the haplogroup from her maternal ancestors. So did Prince Philip, Duke of Edinburgh, whose recorded genealogy traces his female line to Bavaria. Scientists also discovered that famed 16th century astronomer Nicolaus Copernicus traced his maternal lineages to haplogroup H.
What do people with the surname Riordan have in common?
Spoiler alert: it's complicated. People with the same last name are usually no more genetically similar than a randomly sampled group of people from the same population. That said, people with the same surname are more likely to have similar ancestries than randomly sampled individuals. The reason is the tendency of people with similar cultural or geographical backgrounds to preferentially mate with one another. That's why people who share a surname may be more likely to share traits and tendencies in common than people within the general population. Check out the percentages below to see the prevalences of tastes, habits, and traits of people with your surname compared with prevalences among 23andMe users.
Preferences
Chocolate Ice Cream
Prefers chocolate flavored ice cream over other flavors.
"Riordan" Surname 32.6%
23andMe Users 41.3%
Traits
Misophonia
When sounds made by others, like the sound of chewing or yawning, provoke strong emotional reactions in an individual.
"Riordan" Surname 22.1%
23andMe Users 27.9%
Habits
Sugary Drink
Drinks one or more sugary drinks per day.
"Riordan" Surname 25.9%
23andMe Users 21.1%
Wellness
Migraine
A severe headache characterized by intense pain, sensitivity to light and sound, and often accompanied by nausea and vomiting.
"Riordan" Surname 14.4%
23andMe Users 16.4%
Are health conditions linked to the last name Riordan?
The short answer is that, if there is an association between surname and health, it's usually more about your ancestry than your name. Individuals with a given surname are no more genetically similar than the general population but often have similar ancestries. The populations of people associated with those shared ancestries often have sets of genetic variations, also known as alleles, in common. Some of those alleles are associated with a greater likelihood of developing certain diseases.
Disease variant frequency by ancestry
Disease allele frequencies in populations associated with the surname Riordan are shown below. Important Note: not everyone with a disease allele will develop these health condition