The O'CALLAGHAN surname in the USA

Frequency Comparisons
	Total	Rank	Frequency %	Per million people
United States
United States (Current snapshot)	2,779	10588	0.001	10
United States (1880 census)	85	35067	0	2
Change since 1880	+2694	+24479	+N/A	+8
Other Countries
Australia	20	51633	0	1
United Kingdom	369	11058	0.001	8

Top States for O'CALLAGHAN by Total
State	Total	Rank in State	Frequency %	Per million people
California	328	7540	0.001	10
New York	303	5860	0.002	16
Massachusetts	293	2734	0.005	46
Florida	191	8949	0.001	12
Illinois	165	7192	0.001	13
Top States for O'CALLAGHAN by Frequency
State	Total	Rank in State	Frequency %	Per million people
Massachusetts	293	2734	0.005	46
New Hampshire	35	4417	0.003	28
Connecticut	80	5228	0.002	23
Nebraska	32	7914	0.002	19
New Jersey	140	6346	0.002	17

Notes

Total is the total number of people with that surname.
Rank is the position in the list of names ordered by total (eg, a rank of 1 means that it's the most common name, and a rank of 10 means it's the tenth most common, etc).
Frequency is the percentage of people with that surname.
Per million people is the number of people with that surname per million of the population.

'A figure of zero indicates that we don't have data for this name (usually because it's quite uncommon and our stats don't go down that far). It doesn't mean that there's no-one with that name at all!

For less common surnames, the figures get progressively less reliable the fewer holders of that name there are. This data is aggregated from several public lists, and some stats are interpolated from known values. The margin of error is well over 100% at the rarest end of the table!

For less common surnames, the frequency and "per million" values may be 0 even though there are people with that name. That's because they represent less than one in a million of the population, which ends up as 0 after rounding.

It's possible for a surname to gain in rank and/or total while being less common per million people (or vice versa) as there are now more surnames in the USA as a result of immigration. In mathematical terms, the tail has got longer, with a far larger number of less common surnames.

Figures for top states show firstly the states where most people called O'CALLAGHAN live. This obviously tends to be biased towards the most populous states. The second set of figures show where people called O'CALLAGHAN represent the biggest proportion of the population. So, in this case, there are more people called O'CALLAGHAN in California than any other state, but you are more likely to find a O'CALLAGHAN by picking someone at random in Massachusetts than anywhere else.

Classification and Origin of O'CALLAGHAN

Region of origin: British Isles

Country of origin: Ireland

Language of origin: Gaelic

Ethnic origin: Celtic

Religious origin: Christian

Name derivation: From name of parent

Data for religion and/or language relates to the culture in which the O'CALLAGHAN surname originated. It does not necessarily have any correlation with the language spoken, or religion practised, by the majority of current American citizens with that name.

Data for ethnic origin relates to the region and country in which the O'CALLAGHAN surname originated. It does not necessarily have any correlation with the ethnicity of the majority of current American citizens with that name.

Ethnic distribution of O'CALLAGHAN in the USA

Classification	Total	Percent
Mixed Race	34	1.22
White (Hispanic)	31	1.12
Asian/Pacific	19	0.68
Black/African American	6	0.22
White (Caucasian)	2,689	96.76
Native American/Alaskan	Less than 100	0

Ethnic distribution data shows the number and percentage of people with the O'CALLAGHAN surname who reported their ethnic background as being in these broad categories in the most recent national census.

Similar names to O'CALLAGHAN

The following names have similar spellings or pronunciations as O'CALLAGHAN.

This does not necessarily imply a direct relationship between the names, but may indicate names that could be mistaken for this one when written down or misheard.