| Surname | Country | State | County or Province | From | To | Member |
|---|---|---|---|---|---|---|
| Gackowski | C014-1 | |||||
| Gaet/Gaeti/Gaetta/Gaetto | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1600 | 1730 | J009-1 |
| Galas | Germany/Poland | Mur Goslina Parish | Poznan | 1811 | 1857 | R003-1 |
| Gallagher | W008-1 | |||||
| Gallas | Germany/Poland | Mur Goslina Parish | Poznan | 1811 | 1857 | R003-1 |
| Gallegher | Ireland | County Donegal | G015-1 | |||
| Gallo | Italy | Piemonte | Asti | 1770 | 1850 | J009-1 |
| Gamberton | France | D013-2 | ||||
| Gamberton | USA | New Jersey | Middlesex County | 1750 | present | D013-2 |
| Gardet/Gardette | France | Périgord | Dordogne | 1600 | 1667 | J009-1 |
| Gardner | USA | New York | Oneida County | 1800 | 1950 | H012-1 |
| Gardner | USA | Pennsylvania | Somerset County | N006-1 | ||
| Gardner | USA | New York | 1750 | 1830 | P003-2 | |
| Gardner | USA | Ohio | Cuyahoga County | 1830 | 1900 | P003-2 |
| Garin/Garino | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1565 | 1883 | J009-1 |
| Garrel/Garello | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1540 | 1651 | J009-1 |
| Garrett | USA | Tennessee | Sumner County | 1820 | 1950 | C022-1 |
| Garrett | USA | Illinois | Pope County | L006-1 | ||
| Garrett | USA | Tennessee | Davidson County | 1820 | 1950 | C022-1 |
| Garrett | USA | Tennessee | Bedford County | L006-1 | ||
| Garrett | USA | Tennessee | Robertson County | 1820 | 1950 | C022-1 |
| Garrett | USA | Virginia | L006-1 | |||
| Gastalda/Gastaldo | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1570 | 1703 | J009-1 |
| Gaubert | France | Provence-Alpes-Côte-d'Azur | Alpes de Haute Provence | 1670 | 1788 | J009-1 |
| Gautier/Gautiero | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1569 | 1805 | J009-1 |
| Gedvitius | Lithuania | Silale | 1852 | T004-2 | ||
| Geha | Lebanon | Zahle | 1700 | present | P010-1 | |
| Gentry | USA | Kentucky | P013-1 | |||
| Gentry | USA | Missouri | Marion County | P013-1 | ||
| George | USA | MD | Baltimore | 1795 | 1930 | D011-1 |
| Gerald | G013-1 | |||||
| Gerard | USA | Missouri | Osage County | 1850 | J005-1 | |
| Gerard | France | Alsace-Lorraine | 1700 | 1900 | J005-2 | |
| Gerard | USA | Missouri | Calloway County | 1850 | J005-1 | |
| Gerkins | Germany | 1825 | Present | G009-1 | ||
| Gerkins | USA | Ohio | Wood County | 1825 | Present | G009-1 |
| Gerkins | USA | Ohio | Lucas County | 1825 | Present | G009-1 |
| Getty | USA | Pennsylvania | Montgomery County | 1740 | 1780 | G001-1 |
| Gillick | Ireland | County Meath | 1800 | 1850 | N001-1 | |
| Gillick | Canada | Quebec | Sherbrooke County | 1840 | 1855 | N001-1 |
| Gillick | USA | Minnesota | McLeod County | 1855 | present | N001-1 |
| Ginty | Ireland | County Mayo | Killasser | 1830 | present | B026-2 |
| Giordan/Giordana/Giordano | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1570 | 1703 | J009-1 |
| Girard | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1760 | 1857 | J009-1 |
| Girkins | Germany | 1825 | Present | G009-1 | ||
| Girkins | USA | Ohio | Lucas County | 1825 | Present | G009-1 |
| Girkins | USA | Ohio | Wood County | 1825 | Present | G009-1 |
| Glass | 1895 | present | I002-1 | |||
| Glass | USA | Illinois | Cook County | 1895 | present | I002-1 |
| Glauber | Czech Republic | Bohemia | Langenderflas | bef 1750 | 1900 | F010-2 |
| Gleason | USA | Illinois | Cook County (Chicago) | 1880 | 1922 | B003-1 |
| Glimme | Norway | Voss | 1799 | 1878 | T007-1 | |
| Gnadt | USA | Missouri | Osage County | 1850 | J005-1 | |
| Gnadt | USA | Missouri | Calloway County | 1850 | J005-1 | |
| Godwin | USA | Georgia | 1800's | C017-1 | ||
| Goiran | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1589 | 1680 | J009-1 |
| Golden | M027-1 | |||||
| Goulding | England | D005-1 | ||||
| Goulding | USA | Kansas | Douglas County | D005-1 | ||
| Goulding | USA | Kansas | Shawnee County | D005-1 | ||
| Gradowski | Poland | Wabrzezno | 1700 | 1850 | S017-1 | |
| Graham | USA | Ohio | Meigs County | A007-1 | ||
| Granger | USA | Minnesota | Itasca | 1910 | 1940 | A009-1 |
| Greer | USA | Tennessee | Robertson County | 1790 | 1950 | C022-1 |
| Gregg | United Kingdom | M028-1 | ||||
| Gregg | USA | Illinois | ||||
| Griffin | Ireland | County Cork | 1811 | 1866 | D011-1 | |
| Grimes | W008-1 | |||||
| Grobbel | Germany | M026-1 | ||||
| Grobbel | USA | Michigan | M026-1 | |||
| Gross | USA | Ohio | Wood County | 1850 | present | A009-1 |
| Gross | Germany | Palatinate | bef 1736 | W010-1 | ||
| Gruecek | Poland | Boldury | 1850 | Present | H014-1 | |
| Gruel | Germany | Pommerania | 1875 | 1990 | G015-1 | |
| Gruel | USA | Indiana | Lake County | 1875 | 1990 | G015-1 |
| Gruntmeyer | Lithuania | City Trocki Vilnius | 1745 | 1889 | H011-1 | |
| Grzybowski | Poland | Wabryezno | 1700 | 1875 | S017-1 | |
| Guerin | Ireland | County Clare | 1830 | present | W006-1 | |
| Guiglaris/Juglaris | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1510 | 1708 | J009-1 |
| Guigonia/Guigonis | France | Provence-Alpes-Côte-d'Azur | Alpes-Maritimes | 1650 | 1701 | J009-1 |
| Guill | Luxembourg | Grevenmacher (Town) | bef 1845 | W010-1 | ||
| Guirsch | Luxembourg | 1735 | present | S005-1 | ||
| Gustafson | Sweden | bef 1892 | A005-1 | |||
| Gustafson | USA | Illinois | 1892 | present | A005-1 | |
| Gustke | Germany | C002-1 | ||||
| Gutenberg | Germany | H001-1 | ||||
| Guttman | Poland | Wabrzezno | 1700 | 1900 | S017-1 | |
| Gyzmaite | Lithuania | Silale | Silale | 1852 | T004-2 |