| Name | # Entries |
|---|---|
| Ismail | 928 |
| Isaacs | 721 |
| Irvine | 375 |
| Ireland | 303 |
| Ingram | 280 |
| Irving | 252 |
| Inglis | 221 |
| Innes | 204 |
| Isaac | 148 |
| Ingham | 106 |
| Immelman | 85 |
| Ibrahim | 75 |
| Ives | 60 |
| Iles | 57 |
| I | 56 |
| Idea | 55 |
| Illingworth | 48 |
| Isherwood | 44 |
| Ivory | 44 |
| Ingle | 41 |
| Irwin | 40 |
| Information | 36 |
| In | 34 |
| Inkster | 34 |
| Israel | 32 |
| Ismael | 30 |
| Imrie | 30 |
| International | 30 |
| Insley | 29 |
| Iremonger | 28 |
| Isbister | 25 |
| Independent | 25 |
| Idas | 24 |
| Intyre | 24 |
| Iqbal | 24 |
| Indian | 24 |
| Ilam | 23 |
| Impey | 23 |
| Ibbotson | 23 |
| Industrial | 23 |
| Ihaka | 23 |
| Islam | 22 |
| Ivey | 21 |
| Ian | 21 |
| Invercargill | 20 |
| Isaacson | 20 |
| Iversen | 20 |
| Inger | 19 |
| Indigo | 18 |
| Iyer | 18 |
| Institute | 17 |
| Ikin | 16 |
| Irons | 15 |
| Italian | 14 |
| Inderjeeth | 14 |
| Inggs | 14 |
| Inner | 14 |
| Ingley | 13 |
| Imperial | 13 |
| Inside | 13 |
| Island | 13 |
| Ilsley | 12 |
| Inder | 12 |
| Image | 11 |
| Iron | 11 |
| Isaks | 11 |
| Isemonger | 11 |
| Ibell | 10 |
| Iakopo | 10 |
| Inns | 10 |
| Impact | 10 |
| Iwikau | 10 |
| Ivamy | 9 |
| Illing | 9 |
| Intosh | 9 |