1861 Census - surnames beginning with I
| Last Name | First Name | Age | Parish | Piece | Folio | Page |
| IAN | Alice Jane | 14 | Douglas | 4419 | 91 | 112 |
| IAN | Anne | 50 | Douglas | 4419 | 91 | 112 |
| IAN | Anne Mary | 16 | Douglas | 4419 | 91 | 112 |
| IAN | Kate | 12 | Douglas | 4419 | 91 | 112 |
| IAN | John Tindall | 46 | Douglas | 4419 | 91 | 112 |
| ICK | Emily F. | 38 | Douglas | 4419 | 47 | 10 |
| IDDON | Thomas | 20 | Ramsey | 4429 | 46 | 6 |
| IDDON | William | 55 | Ramsey | 4429 | 46 | 6 |
| IMISH | George | 13 | Douglas | 4419 | 105 | 53 |
| INGHAM | Edward | 5 | Ballaugh | 4411 | 20 | 54 |
| INGHAM | Richard | 16 | Onchan | 4415 | 63 | 97 |
| INGLEBY | Arthur | 7 | Onchan | 4415 | 77 | 201 |
| INGLEBY | Charles | 3 | Onchan | 4415 | 77 | 201 |
| INGLEBY | Ellen | 10 | Onchan | 4415 | 77 | 201 |
| INGLEBY | Margaret | 35 | Onchan | 4415 | 77 | 201 |
| INGLEBY | William | 43 | Onchan | 4415 | 77 | 201 |
| INGLIS | Isabella | 25 | Douglas | 4416 | 58 | 108 |
| INGLIS | John | 24 | Douglas | 4416 | 58 | 108 |
| INGLIS | John | 1 | Douglas | 4416 | 58 | 108 |
| INGLIS | William | 2 | Douglas | 4416 | 58 | 108 |
| INMAN | Catherine | 2 | Douglas | 4418 | 81 | 266 |
| INMAN | Charlotte | 37 | Douglas | 4418 | 81 | 266 |
| INMAN | John | 7 | Douglas | 4418 | 81 | 266 |
| INMAN | Owen | 40 | Douglas | 4418 | 81 | 266 |
| INNES | Amelia A. M. | 41 | Douglas | 4419 | 108 | 83 |
| INNES | Amelia A. M. M. | 5 | Douglas | 4419 | 108 | 83 |
| INNES | Beatrice G. | 3 | Douglas | 4419 | 108 | 83 |
| INNES | George G. | 7 | Douglas | 4419 | 108 | 83 |
| INNES | Isabella V. J. R. | 18 | Douglas | 4419 | 108 | 83 |
| INNES | James | 54 | Douglas | 4419 | 108 | 83 |
| IRAKAY | Amas | 80 | Douglas | 4418 | 81 | 267 |
| IRELOW | Ellen | 20 | Douglas | 4419 | 88 | 70 |
| IRETON | Ann | 19 | Douglas | 4419 | 36 | 40 |
| IRVINE | Alexander | 8 | German | 4420 | 8 | 37 |
| IRVINE | Alice | 20 | German | 4420 | 8 | 37 |
| IRVINE | Bartholemew | 52 | Castletown | 4414 | 29 | 74 |
| IRVINE | Elizabeth | 6 | German | 4420 | 8 | 37 |
| IRVING | James | 65 | Braddan | 4412 | 36 | 122 |
| IRVINE | James A. | 43 | German | 4420 | 8 | 37 |
| IRVINE | James J | 10 | German | 4420 | 8 | 37 |
| IRVING | Lelly | 78 | Douglas | 4418 | 78 | 224 |
| IRVINE | Margaret | 42 | German | 4420 | 8 | 37 |
| IRVINE | Martha | 13 | German | 4420 | 8 | 37 |
| IRVINE | Mary | 24 | Castletown | 4414 | 29 | 74 |
| IRVINE | Mary | 1y 6m | German | 4420 | 8 | 37 |
| IRVINE | Samuel | 82 | Castletown | 4414 | 29 | 74 |
| IRVINE | Samuel | 35 | Castletown | 4414 | 29 | 74 |
| IRVINE | Susan | 14 | Castletown | 4414 | 29 | 74 |
| IRVINE | William | 22 | German | 4420 | 8 | 37 |
| ISEDALE | Ann | 56 | Douglas | 4417 | 27 | 259 |
| ISDALE | Ann | 19 | Douglas | 4417 | 16 | 165 |
| ISDALE | Frances | 14 | Douglas | 4419 | 47 | 11 |
| ISDALE | Isabella | 54 | Douglas | 4417 | 16 | 165 |
| ISDALE | James | 13 | Douglas | 4417 | 16 | 165 |
| ISDALE | Sarah | 28 | Douglas | 4419 | 24 | 223 |
| ISDALE | William | 26 | Douglas | 4419 | 24 | 223 |
| ISDALE | William | 21 | Douglas | 4417 | 16 | 165 |
| ISHERWOOD | Elizabeth | 44 | Onchan | 4415 | 11 | 71 |
| ISLES | Sarah A. | 24 | Douglas | 4416 | 13 | 90 |
| ISLES | William J. | 38 | Douglas | 4416 | 13 | 90 |
| ISSI | Cecilia J. | 20 | Onchan | 4415 | 78 | 206 |
| ISSI | Elizabeth R. | 17 | Onchan | 4415 | 78 | 206 |