| Irwin | P. | Napier. 5861, Albany | P1J and 19A, 108B | 1962 |
| Irwin (Upper) Roads Board | - | Commonage and Reserves, Box 16, Mingenew | U2R | 1924 |
| Isaac | M. B. | Lots 98, 99, 100, 489, Tambellup | Y1S | 1912 |
| Isaac | M. B. | Lots 98, 99, 489, Tambellup | Y1S | 1924 |
| Isaacs | Chas. F. | Boomerang. Peel Estate, Jandakot | 1FQ | 1924 |
| Isaacs | M. A. E. | Town Lot 28, Margaret River | 1ZS | 1962 |
| Isaksen | Hilmer | Ranch Farm, Katanning | H1T | 1912 |
| Isaksen | Hilmer | Ranch Farm, Katanning | H1T | 1924 |
| Isbister | F. W. | Westbank, York | FW8 | 1912 |
| Isbister | F. W. | Westbank, York | FW8 | 1924 |
| Isbister | G. W. | Fargo, Kwolyin, via York | Y9K | 1924 |
| Isbister | M. L. | Ranfurly Park, Moora | M1Z and 16D, 107E | 1962 |
| Isbister Bros. | - | Glenorchy, Williams | 1BW | 1912 |
| Isbister Bros. | - | Glenorchy, Williams | 1BW | 1924 |
| Isdell | Jas. | P.O. Hall's Creek | 2JU | 1912 |
| Isdell | Jas. | P. O. Hall's Creek | 2JU | 1924 |
| Isdell Pastoral Co. Ltd. | - | Isdell Station, via Derby | UY0 | 1924 |
| Isele | F. F. | Mariginup Lake, Wanneroo | FV4 | 1924 |
| Iseppi | C. | Woodland Park, Hamel | UH3 and 50B, 10E | 1962 |
| Iseppi | J. H. | Block 55/66 Drake-Brook District, Waroona | 1JH and 11C, 26E | 1962 |
| Ison | Edward | Tablelands, Roebourne | NS0 | 1924 |
| Ispen & Sons | J. B. | Chungarrup, Manjimup | J1E and 20B, 112E | 1962 |
| Isseka | Jack | Four Mile Well, Murchison River, Northampton | J3O | 1912 |
| Isseka | Jack | Four-Mile Well, Murchison River, Northampton | J3O | 1924 |
| Italiano | C. | 5135-4-3-2 Woodinilling Locs, Kojonup | CJ7 and 12B, 36E | 1962 |
| Italiano | D. A. | Port .Wellington Loc. I being part of each lot 29, 30-1, on plan 2003, Brunswick Junction | DA9 and 34D, 8E | 1962 |
| Italiano | G. | Block 1831, Bindoon | GT7 and 40A, 12B | 1962 |
| Italiano | P. & F. | 37 Pt. 128, Dardanup | 1RO and 38C, 103E | 1962 |
| Italiano & Sons | P. (Mrs) | Wellington Loc. Lot 802, 1A, Harvey | P2S and 9B, 24E | 1962 |
| Ittershagen | Hermann C. | Thuringia, Manjimup | 1TZ | 1924 |
| Ivan | R. & M. | Greystones, Williams | 1ER and 35B, 35A | 1962 |
| Ivanhoe Grazing Co. Pty. Ltd. | - | Ivanhoe Station, East Kimberly | H0E and 1C, 17A | 1962 |
| Iverson | F. S. A. | Commonage, Carnarvon | 6NS | 1924 |
| Ives | Aubrey Leonard | Cullaculong, via Peak Hill | L7H | 1926 |
| Ivey | A. J. | Adelong Station, Jilbadji Loc. 124,142, 126, 56, 713, Menzies | 3A7 and 34C, 24A | 1962 |
| Ivey | A. W. | Jilbadji 172, Boadallin | A3W and 30D, 27E | 1962 |
| Ivey | C. F. | Rock-Hill, Welbungin | C8B and 44C, 110A | 1962 |
| Ivey | E. A. E. | Hurstlyn, Bodallin | 8EB and 37C, 7A | 1962 |
| Ivey | E. B. | Jilbadgie 171, Bodallin | EB0 and 34B, 80E | 1962 |
| Ivey | G. A. | 334, 342, 341, 335, Moorine Rock | GA3 and 120D, 25E | 1962 |
| Ivey | G. E. | Loc. 505, 507 and Yuide Eulenlia Station, Kalgoorlie | VE1 and 13C, 71E | 1962 |
| Ivey | J. C. | Jilbadji Loc. 56, Bodallin | 5UJ and 35B, 14A | 1962 |
| Ivey | R.A. | Yindi, Kalggorlie | RA1 and 19B, 104E | 1962 |
| Ivins | L. | Waterdale, Widgiemooltha | 9DT | 1927 |
| Iwankiw | R. | Plant. Loc. 507, Denmark | 0ER and 49B, 120E | 1962 |
| Iwanow | G. | Avon 20091, Ardath | G0J and 103D, 37E | 1962 |
| Izard | Lilian M. | Gleneva, Yuba No. 2 View, Northampton | 7ZA | 1924 |
| Izard | R. A. E. | 6, 12, 15, 45, 46 Seven Springs, Mundaring | R1Z and 20C, 115E | 1962 |
| Izod | Arthur | Yackaranebo, Narrogin | A1Z | 1912 |
| Izod | Arthur | Yackaranebo, Narrogin | A1Z | 1924 |
