| Iredell | F. M. | Drummonds, Loc No. 4461-60, 4413, Manjimup | UF1 | 1962 |
| Iredell | J. S. | Blocks 5282 and 5283, Balbarrup | JZ7 | 1912 |
| Iredell | J. S. | Blocks 5282 and 5283, Balbarrup | JZ7 | 1924 |
| Iredell | T. M. | 4413, 4460, 4461 port, Manjimup | G2D and 38C, 27E | 1962 |
| Ireland | C. R. & H. | White Peak, Geraldton | 1WP and 118E, 54F | 1962 |
| Ireland | E. | Suusex 2894-7, Rosa Brook, Margaret River | 1RE and 37B,71E | 1962 |
| Ireland | G. R. | Nelson Loc. 8340, Merredin | R1G and 117B, 21A | 1962 |
| Ireland | John | Homestead, West Collie | JJ8 | 1912 |
| Ireland | John | Homestead, West Collie | JJ8 | 1924 |
| Ireland | Leslie | Teddington Road, Victoria Park | VU7 | 1924 |
| Ireland | M.C. | 17 Salsbury Street, Bayswater | QG1 | 1962 |
| Ireland | Margaret C. | Roselea, Nedlands | QG1 | 1924 |
| Ireland | N. R. | Ferndale, Ongerup | ZR8 and 24E, 43C | 1962 |
| Ireland | V. C. | Yongermere, Borden | VC1 and 114A, 19B | 1962 |
| Ireland & Wheeldon | W. & E. A. | Woodlands, Northampton | UW1 | 1924 |
| Irlam | R. B. | Peninsula, Maylands | R8J | 1912 |
| Irlam | R. B. | Peninsula, Maylands | R8J | 1924 |
| Ironmonger | C. C. | Kinville, Karridale | UC8 | 1962 |
| Ironmonger | C. H. | Colmyn, Karridale | H4W and 10C, 49A | 1962 |
| Ironmonger | Charles H. | Woodvale, Wonnerup | H4W | 1927 |
| Irvin | Samuel | Hazeldere, Mt. Barker | S1V | 1912 |
| Irvin | Samuel | Hazeldene, Mt. Barker | S1V | 1924 |
| Irvine | A. E. | Dowerin | AE6 | 1924 |
| Irvine | Hans W. H. | Kockatea, Mullewa | 1HU | 1912 |
| Irvine | Hans W. H. | Kockatea, via Mullewa | 1HU | 1924 |
| Irvine | J. T. | Passen Dale,Chidlows | DT0 and 33A, 117B | 1962 |
| Irvine | M. A. | Sandhurst, Dowerin | AE6 and 27A, 3C | 1962 |
| Irvine | Margaret | Daylup, Esperance Bay | 1RV | 1912 |
| Irvine | R. S. | Taradale, Queens Park | S1V | 1962 |
| Irvine | Robert | Oakfield Farm, Yellingup, Katanning East | 7NE | 1912 |
| Irvine | Robt. | Oakfield Farm, Yellingup, East Katanning | 7NE | 1924 |
| Irvine | Wm. G. | Onslow Creek, Carnarvon | CQ1 | 1924 |
| Irvine & Irvine | - | Bedarlo, Bencubbin | 1ZY | 1924 |
| Irvine & Son | C. R. | Riverview, Busselton | 1ZY and 6B, 51F | 1962 |
| Irving | A. N. G. | Kojonup 5967, 6498, Cranbrook | 7GV and 26B 12E | 1962 |
| Irving | Archd. Nigel Guy | Gingelup, Bon Shaw, Cranbrook, Kojonup | 7GV | 1924 |
| Irving | F. W. MacG. | Bonshaw, Cranbrook | FV6 and 40A, 4C | 1962 |
| Irving | Geo. | Bonshaw, Kojonup | 8GG | 1912 |
| Irving | Geo. | Bonshaw, Kojonup | 8GG | 1924 |
| Irving | George | Townfoot, Parker's Road, Souther Cross | Q0Y | 1925 |
| Irving | I. N. | Koorda | 9VN | 1924 |
| Irving | Margaret L. | Merrie Shields, Tenterden | M9V | 1924 |
| Irving | R. C. | Bealing Wellington Loc. 206, Lowden | XF8 and 11A, 14C | 1962 |
| Irving | W. W. | Merrie Shields, Cranbrook | M9V and 80B, 47A | 1962 |
| Irving & Douglas | - | Chenus Station, Nannine | 1DN | 1912 |
| Irving & Smith | - | Mooloogool, Meekatharra | O4O | 1924 |
| Irving & Smith | - | Mingah, Meekatharra | OO4 | 1924 |
| Irving & Son | G. | Townfoot, Moorine Rock | Q0Y and 8B, 48E | 1962 |
| Irwin | A. E. | Homestead, Dowerin | AE6 | 1912 |
| Irwin | A. E. | Homestead, Dowerin | AE6 | 1924 |
