| Tremlett | W. E. | Tammin | W7T | 1924 |
| Tremlett | W. H. | Avon 22673, 15810, 20834, Tammin | W7T and 33B, 48A | 1962 |
| Trenordan | H. O. | Roe 23506, Karlgarin | H0T and 48B, 108A | 1962 |
| Trenorden | John W. | Williams Loc. 8446, 86-Gate, Wickepin | T7O | 1912 |
| Trenorden | John W. | Williams Loc. 8446, 86 Gate, Wickepin | T7O | 1924 |
| Trenorden | R. F. | Khayyami, Yelbene | RT6 and 27B, 7E | 1962 |
| Trenorden & Sons | H. J. | Tamar, 22244, Wyalkatchem | HJ7 and 22D, 67E | 1962 |
| Trenorden Bros. | - | Blocks 17684 /55, 6315 /74, Korrelocking | BT5 | 1912 |
| Trenorden Bros. | - | Blocks 17684/55, 6315/74, Korrelocking | BT5 | 1924 |
| Trenowden | F. | Aloba, Moora | F2T and 6C, 119E | 1962 |
| Trenoweth | G. R. | Locs. 118, 119 & 1165, Gosnells | GT3 | 1912 |
| Trenoweth | G. R. | Locs. 118, 119, and 1165, Gosnells | GT3 | 1924 |
| Trent | A. F. | Indiana, Noggerup | 6AT and 29B, 117E | 1962 |
| Trent | J. B. & N. B. | Part of Plantagenet 31, Mt. Barker | TC5 and 32B, 111E | 1962 |
| Trent | T. W. & P. G. | 31 and 1773, Mt. Barker | TW6 and 26B, 84E | 1962 |
| Trent & Sons | C. G. | Kentucky, Mt. Barker | T3T and 45B, 47A | 1962 |
| Tresise | P. C. | Moy, Byford | 3PT and 104D, 21E | 1962 |
| Tresize | E. G. | Wendowie, Baandee | E7T | 1924 |
| Tresize | Simon | 14 Melbourne Street, Brown Hill | 3TZ | 1924 |
| Trestrail | C. | Lot 2, Roleystone | T2Q | 1924 |
| Trestrail | Jas. | Beering Farm, Popnyinning | XT2 | 1924 |
| Trestrail | John H. R. | Nelson Loc. 2377, Manjimup | 1TQ | 1924 |
| Trestrail & Son | S. J. | Oakleigh, Karlgarin | XT2 and 30B, 7E | 1962 |
| Trethowan | B. M. A. (Mrs) | Maybenup, Kojonup | D0J and 11D, 54F | 1962 |
| Trethowan | J. S. | Weedarra, Kojonup | 1TB and 12C, 34E | 1962 |
| Trevaski | J. | Cornubia Run, Tambellup | XT3 | 1912 |
| Trevaskis | J. | Cornubia Run, Tambellup | XT3 | 1924 |
| Trevaskis | R. D. B. | Plantagenet Locs. 2745, 3648, Tainbellup | R2T and 44C, 26E | 1962 |
| Trevaskis | W. L. C. | Cornubia, Wickepin | 2TU | 1924 |
| Trevaskis & Sons | P. S. | Cornubia, Tambellup | XT3 and 38C, 21A | 1962 |
| Trevena | Edwin | Strathnairn, Upper Preston | E2T | 1912 |
| Trevena | Edwin | Strathnairn, Upper Preston | E2T | 1924 |
| Trevena | R. E. | Strathnairn, Donnybrook | E2T and 51F, 16D | 1962 |
| Trevenen | J. B. | Addiston, Tambellup | BT7 and 38C, 42E | 1962 |
| Trevenen | P. & N. | Wellington 2979 and 48, Cookernup | 4PT and 104B, 21E | 1962 |
| Trevenen | P. E. | Williams Loc. 13088, Lake Grace | 6PT and 52F, 12C | 1962 |
| Trevenen | S. A. | Spring Creek, Cookernup | S7T and 49B, 28E | 1962 |
| Trevenen | W. A. | Windalya, Roe 872-3, Buniche | 2TN and 12B, 112A | 1962 |
| Trevor | Chas. | Block 641, Kununoppin, Mulgi via Dowerin | CT9 | 1912 |
| Trevor | Chas. | Block No. 641, Kununoppin, Mulgi, vi Dowerin | CT9 | 1924 |
| Trew | H. | Woodbyrne, Carlotta, via Nannup | TR9 | 1962 |
| Treylen | Wm. | Maccarme, Wooraloo | W5T | 1912 |
| Trezise | E. D. | Pendeen, Marradong | A4T and 20D, 21E | 1962 |
| Triat | Ellen | Nine Springs, Isseka | ET5 | 1924 |
| Trichet | W. E. | 1635, East Wanneroo | 2WT and 56F, 21B | 1962 |
| Trickett | R. & R. A. C. | Avondale, Coolup | 1HP and 6C, 17E | 1962 |
| Trickett | Ronald | Oakford, Coolup | TX9 | 1924 |
| Trickett | S. | Quailing Dale, Darkan | UT4 | 1912 |
| Trickett | S. | Quailing Dale, Darkan | UT4 | 1924 |
| Trifonoff | T. K. | Nelson 9197, Manjimup | YX6 | 1962 |
