| Surname | Country | State | County or Province | From | To | Member |
|---|---|---|---|---|---|---|
| Caire | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1550 | 1616 | J009-1 |
| Calkins | USA | New York | Madison County | 1780 | 1870 | B023-1 |
| Calvina | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | J009-1 | ||
| Calzabame | Italy | Trentino | Alto Adige | 1700 | 1770 | J009-1 |
| Camos/Camossa/Camous | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1570 | 1653 | J009-1 |
| Campbell | Scotland | D011-1 | ||||
| Canning | Ireland | Meath County | 1800 | 1850 | ||
| Caravello | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1570 | 1670 | J009-1 |
| Carberry | Ireland | bef 1820 | 1820 | M019-1 | ||
| Carberry | Canada | Newfoundland | 1820 | present | M019-1 | |
| Carberry | Canada | New Brunswick | 1820 | present | M019-1 | |
| Carberry | USA | Wisconsin | 1820 | present | M019-1 | |
| Carbery | Ireland | bef 1820 | 1820 | M019-1 | ||
| Carbery | Canada | Newfoundland | 1820 | present | M019-1 | |
| Carbery | Canada | New Brunswick | 1820 | present | M019-1 | |
| Carbery | USA | Wisconsin | 1820 | present | M019-1 | |
| Carbey | Ireland | bef 1820 | 1820 | M019-1 | ||
| Carbey | Canada | Newfoundland | 1820 | present | M019-1 | |
| Carbey | Canada | New Brunswick | 1820 | present | M019-1 | |
| Carbey | USA | Wisconsin | 1820 | present | M019-1 | |
| Carey | USA | Missouri | Marion County | P013-1 | ||
| Carey | USA | Kentucky | P013-1 | |||
| Carguia | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1530 | 1610 | J009-1 |
| Carles | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1586 | 1718 | J009-1 |
| Carlin/Carlina/Carlino | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1600 | 1734 | J009-1 |
| Carlsen | Denmark | Droninglund | Asa | J009-1 | ||
| Carlson | USA | Illinois | 1881 | present | A005-1 | |
| Carlson | Sweden | bef 1881 | A005-1 | |||
| Carlson | Sweden | 1851 | 1884 | O001-1 | ||
| Carlson | USA | Minnesota | St. Louis County | 1884 | 1996 | O001-1 |
| Carlson | USA | Minnesota | Hennepin County | 1884 | 1996 | O001-1 |
| Carnegie | USA | New York | Jefferson County | 1800 | present | F008-1 |
| Carrison | A010-1 | |||||
| Carroll | USA | Maryland | Howard County | 1840 | present | H018-1 |
| Carter | A010-1 | |||||
| Carthy | USA | Illinois | Cook County | 1860s | present | N001-2 |
| Carthy | USA | Illinois | Cook County | 1860s | present | N001-2 |
| Carthy | USA | Illinois | DuPage County | 1860s | present | N001-2 |
| Carthy | USA | Illinois | Kane County | 1860s | present | N001-2 |
| Carthy | USA | Illinois | Will County | 1860s | present | N001-2 |
| Cary | A010-1 | |||||
| Cary | USA | Missouri | P013-1 | |||
| Cary | USA | Kentucky | P013-1 | |||
| Cassebaum | Germany | Westphalia | Oldendorf | 1730 | 1850 | B018-1 |
| Cassebaum | Germany | Westphalia | Holzhausen | 1730 | 1850 | B018-1 |
| Cassebaum | Germany | Westphalia | Blasheim | 1730 | 1850 | B018-1 |
| Caulkings | USA | New York | Madison County | 1780 | 1870 | B023-1 |
| Cavallo | Italy | Piemonte | Asti | 1770 | 1899 | J009-1 |
| Cavallo | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1900 | 1974 | J009-1 |
| Cawley | Ireland | County Sligo | Kilmacteigue | 1840 | present | B026-2 |
| Cebulski | USA | Illinois | Cook County (Chicago) | 1880 | 1900 | B003-1 |
| Chabanne/Chabanes/de Chabanes | France | Périgord | Dordogne | 1615 | 1851 | J009-1 |
| Chacharowska | USA | Illinois | Cook County (Chicago) | 1875 | 1930 | B003-1 |
| Champlin | USA | Virginia (now WV) | Wood County | 1830 | 1920 | O001-1 |
| Champlin | USA | Ohio | Vinton County | 1830 | 1920 | O001-1 |
| Champlin | USA | Iowa | Black Hawk County | 1830 | 1920 | O001-1 |
| Champlin | USA | Iowa | Jasper County | 1830 | 1920 | O001-1 |
| Chapnick | Poland | 1880 | present | I002-1 | ||
| Chapnick | USA | Illinois | Cook County | 1880 | present | I002-1 |
| Charles | England | 1842 | 1862 | F009-1 | ||
| Charles | USA | Wisconsin | Racine County | 1862 | present | F009-1 |
| Chassayneau/Chassagnou | France | Périgord | Dordogne | 1715 | 1808 | J009-1 |
| Chastan | France | Provence-Alpes-Côte-d'Azur | Alpes de Haute Provence | 1620 | 1779 | J009-1 |
| Chasteen | USA | Indiana | Jefferson County | 1830 | present | O001-1 |
| Chasteen | USA | Indiana | Marion County | 1830 | present | O001-1 |
| Chasteen | USA | Missouri | Jackson County | 1830 | present | O001-1 |
| Chateau | France | Périgord | Dordogne | 1730 | 1680 | J009-1 |
| Chiarlone/Ciarlone | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1576 | 1673 | J009-1 |
| Chichester | A010-1 | |||||
| Chidester | England | 1800 | present | A010-1 | ||
| Chidester | USA | New York | Otsego County | 1800 | present | A010-1 |
| Chidester | USA | Wisconsin | Dane County | 1800 | present | A010-1 |
| Chilton | A010-1 | |||||
| Chlastawa | C014-1 | |||||
| Church | USA | New York | Washington County | 1775 | 1818 | F008-1 |
| Church | England | 1710 | 1900 | G014-1 | ||
| Church | USA | Virginia | 1710 | 1900 | G014-1 | |
| Church | USA | Kentucky | 1710 | 1900 | G014-1 | |
| Ciarlone | Italy | Piemonte | Asti | 1770 | 1875 | J009-1 |
| Cieply | Poland | City Keblow | 1860 | present | M030-1 | |
| Cirio | Italy | Piemonte | Asti | 1800 | 1874 | J009-1 |
| Clapp | USA | New York | Washington County | 1750 | 1848 | F008-1 |
| Clapp | USA | Vermont | 1750 | 1848 | F008-1 | |
| Clark | USA | Ohio | 1760 | A007-1 | ||
| Clark | USA | Maryland | 1760 | A007-1 | ||
| Clark | England | Norfolk County | 1800 | present | A010-1 | |
| Clark | Ireland | County Caven | 1814 | 1850 | O006-1 | |
| Clark | USA | Massachusetts | 1640 | 1900 | P012-1 | |
| Clark | USA | Pennsylvania | 1760 | A007-1 | ||
| Clark | USA | Iowa | Mitchell County | 1800 | present | A010-1 |
| Clark | USA | Maine | 1640 | 1900 | P012-1 | |
| Clark | USA | Wisconsin | Dane County | 1800 | present | A010-1 |
| Clarke | D002-1 | |||||
| Clarke | USA | Massachusetts | Norfolk County | 1690 | 1850 | D005-1 |
| Clarke | USA | Massachusetts | Suffolk County | 1690 | 1850 | D005-1 |
| Clarke | USA | Massachusetts | Worcester County | 1690 | 1850 | D005-1 |
| Clarke | USA | Kansas | Douglas County | D005-1 | ||
| Clarke | USA | Kansas | Shawnee County | D005-1 | ||
| Clarke | USA | Oklahoma | Oklahoma County | D005-1 | ||
| Clarke | USA | Oklahoma | Pottawottamie County | D005-1 | ||
| Clay | USA | Virginia | 1620 | present | B016-1 | |
| Clay | USA | Kentucky | 1620 | present | B016-1 | |
| Clay | USA | Illinois | 1620 | present | B016-1 | |
| Clay | USA | Missouri | 1620 | present | B016-1 | |
| Cleland | C020-1 | |||||
| Cleyrat | France | Périgord | Dordogne | 1680 | 1750 | J009-1 |
| Coddington | USA | Illinois | W012-1 | |||
| Cole | USA | Michigan | Washtenaw County | 1835 | 1870 | B035-1 |
| Cole | England | 1600 | present | C002-1 | ||
| Cole | USA | Connecticut | 1626 | present | C002-1 | |
| Cole | USA | New York | 1700 | present | C002-1 | |
| Cole | USA | Ohio | 1800 | present | C002-1 | |
| Cole | USA | Wisconsin | 1900 | present | C002-1 | |
| Colfer | Ireland | County Wexford | Taghmon | 1821 | present | B026-2 |
| Colliflower | USA | Maryland | Washington County | 1720s | A001-1 | |
| Colliflower | USA | Ohio | 1840s | A001-1 | ||
| Collins | USA | Maryland | Frederick County | 1790 | 1832 | N001-1 |
| Collins | USA | New York | Washington County | 1790 | 1830 | T009-1 |
| Collins | USA | Ohio | Harrison County | 1832 | 1900 | N001-1 |
| Collins | USA | Michigan | Calhoun County | 1835 | 1900 | T009-1 |
| Collins | USA | Ohio | Jefferson County | 1857 | 1900 | N001-1 |
| Collins | USA | Ohio | Columbiana County | 1878 | 1900 | N001-1 |
| Comber | Ireland | 1821 | 1848 | K027-1 | ||
| Comber | USA | Pennsylvania | 1848 | present | K027-1 | |
| Compte | France | Périgord | Dordogne | 1620 | 1722 | J009-1 |
| Conley | Ireland | bef 1820 | 1820 | M019-1 | ||
| Conley | USA | Massachusetts | 1820 | present | M019-1 | |
| Conley | USA | Wisconsin | 1820 | present | M019-1 | |
| Connelly | Ireland | bef 1820 | 1820 | M019-1 | ||
| Connelly | USA | Massachusetts | 1820 | present | M019-1 | |
| Connelly | USA | Wisconsin | 1820 | present | M019-1 | |
| Connor | Ireland | B005-1 | ||||
| Connor | Ireland | County Wexford | Taghmon | 1818 | 1850 | B026-2 |
| Connor | USA | Illinois | Cook County (Evanston) | 1850 | present | B026-2 |
| Contesso | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1570 | 1670 | J009-1 |
| Convey | Ireland | County Mayo | Killasser | 1850 | ? | B026-2 |
| Conway | Ireland | County Tipperary | 1850 | C017-1 | ||
| Cooke | A010-1 | |||||
| Cooley | USA | Tennessee | Sumner County | 1800 | 1880 | C022-1 |
| Corbet | Ireland | Cork | 1825 | ? | T004-2 | |
| Corbis | Ireland | County Cork | Cork | T004-2 | ||
| Cord | USA | 1650 | present | C001-1 | ||
| Cornett | USA | Missouri | Audrain County | 1883 | Present | H014-1 |
| Cornwell | USA | Connecticut | 1635 | 1700 | P012-1 | |
| Costa | Italy | Selina | M031-2 | |||
| Cotta | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | J009-1 | ||
| Cottrell | USA | Indiana | Marion County | C006-1 | ||
| Courvelle | USA | Louisiana | S016-1 | |||
| Cowan | Scotland | 1730 | present | C002-1 | ||
| Cowan | Canada | 1750 | present | C002-1 | ||
| Cowan | USA | Michigan | 1900 | present | C002-1 | |
| Cox | Ireland | Mayo | F006-2 | |||
| Cox | USA | Texas | Brazoria County | S016-1 | ||
| Craig | USA | Indiana | Scott County | C006-1 | ||
| Cramer | C004-2 | |||||
| Crapo | A010-1 | |||||
| Croake | Ireland | Kilkenny County | 1800 | 1910 | B023-1 | |
| Croake | USA | Illinois | Cook County | 1850 | 1950 | B023-1 |
| Croft | England | H009-1 | ||||
| Crowe | Ireland | 1860 | present | D015-1 | ||
| Crowley | USA | Maryland | Baltimore City | 1850 | Present | D011-1 |
| Crowley | Ireland | County Cork | 1801 | 1887 | D011-1 | |
| Crown | USA | Illinois | 1887 | 1907 | B019-1 | |
| Crown | USA | Illinois | Cook County | 1887 | 1907 | B019-1 |
| Cubbin | England | H009-1 | ||||
| Cuffman | USA | Tennessee | Sumner County | 1790 | 1980 | C022-1 |
| Cuffman | USA | Tennessee | Davidson County | 1890 | 2005 | C022-1 |
| Cummins | A010-1 | |||||
| Curbello | USA | Texas | 1731 | present | S016-1 | |
| Curbello/Curbelo | USA | Louisiana | S016-1 | |||
| Curbelo | Spain | Canary Islands | 1500 | 1731 | S016-1 | |
| Curti | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1580 | 1691 | J009-1 |
| Cusack | Ireland | County Mayo | Kilmaclasser | 1840 | 1890 | B027-1 |
| Cutler | USA | Massachusetts | WoB Preccinct | 1700 | 1800 | F008-1 |
| Cutler | H022-1 | |||||
| Cyrier | France | 1800 | Present | T011-2 | ||
| Czadowski | C014-1 |