| Name | # Entries |
|---|---|
| Ingram | 1687 |
| Ireland | 1646 |
| Irwin | 1581 |
| Irvine | 1463 |
| Ibrahim | 1044 |
| Inglis | 1029 |
| Irving | 953 |
| Innes | 948 |
| Isaac | 521 |
| Ismail | 507 |
| Ingham | 507 |
| Isaacs | 455 |
| Ison | 439 |
| Iles | 377 |
| Islam Islam | 360 |
| Italiano | 333 |
| Ian | 330 |
| Irvin | 329 |
| Irons | 287 |
| Issa Issa | 278 |
| Iqbal | 271 |
| Ives | 267 |
| Ivory | 254 |
| Inwood | 247 |
| Islam | 245 |
| Ip | 242 |
| Ilic | 236 |
| Ioannou | 232 |
| Ikin | 226 |
| Inman | 212 |
| Ives | 209 |
| Ivey | 206 |
| Izzard | 205 |
| Illingworth | 195 |
| Ivers | 195 |
| Ibbotson | 194 |
| Iacono | 166 |
| Ince | 158 |
| Issa | 158 |
| Isles | 155 |
| Isherwood | 152 |
| Im | 152 |
| Israel | 148 |
| Ioannidis | 147 |
| Ide | 138 |
| Iyer | 137 |
| Ingls | 136 |
| Ivanov | 134 |
| Ivanovic | 132 |
| Ingleton | 130 |
| Ironside | 130 |
| Imrie | 129 |
| Ioane | 124 |
| Inkster | 122 |
| Irish | 120 |
| Isaacson | 117 |
| Isbister | 113 |
| Idris | 111 |
| Ilsley | 110 |
| Iskandar | 108 |
| Ings | 106 |
| Ivan | 106 |
| Illman | 102 |
| Imran | 101 |
| Irani | 101 |
| Ingold | 98 |
| Inch | 97 |
| Imber | 97 |
| Iuliano | 96 |
| Itchens | 96 |
| Ilievski | 96 |
| Ishak | 95 |
| Ing | 94 |
| Iredale | 94 |
| Ivanovski | 93 |