IA ———
Iacampo Ianson(I'Anson)

IB ———
Ibach

IC ———
Icenogle Ickes

ID ———
Iddenden Ide Iddeson Iddings Iddison

IE ———
Ietto(/Yetto)

IG ———
Iggulden Igo

IL ———
Ilgenfritz

IM ———
Imhoff Imlach Immel(/Imel) Impson Imrie Imus

IN ———
Inbody Inch Inche Ingalls Ingelhart Ingersoll Ingle Inglis Ingman Ingram Inkster Inman Inners Insall Inzer

IO ———
Ioannidis Ioannou

HA ———
Irby Ireland Ireton Irion Irish Irmscher Irons Ironside Irvin Irvine Irving Irwin

IS ———
Isaacs Isaacson Isard Isbell Isbister Iseler Iseli(/Isely) Isham Isherwood Ishi Ishmael Isley Isom Ison

IV ———
Ivan(/Ivens/Ivins) Iverson Ives Ivester Ivey Ivie Ivory Ivy

IW ———
Iwaniw

IZ ———
Izaguirre Izard Izat Izlar Izzo