| Thackrah & Ratcliff | Cyril B & Charles F. | Cranliegh, Woodanilling | GR2 | 1927 |
| Thain | B. M. | Loc. 430, Mardella | XU0 | 1924 |
| Thangoo Station Pty. Ltd. | - | Thangoo Station, Broome | R1E and 33D, 28E | 1962 |
| Thatcher | Ernest T. | The Old Homestead, Byford | X4Q | 1925 |
| Thatcher | H. B. | Paradise Farm, Waroona | HT9 | 1912 |
| Thatcher | H. B. | Paradise Farm, Waroona | HT9 | 1924 |
| Thatcher Bros. | - | Wattle Creek, Byford | X4Q and 49C, 20E | 1962 |
| Thaxter | F. D. & D. J. | Bellbird Plains, Dalwallinu | D9T and 30D, 120E | 1962 |
| Thayer | William H. | Esperance Loc. 512, Scaddan | WT6 | 1928 |
| The Benedictine Comm. of New Norcia (Inc.) | - | Kalumbra, via Wyndham | DR8 and 6D, 21E | 1962 |
| The Cooralya Pastoral Co. | - | Cooralya Station, Carnarvon | 1MU and 71C, 51F | 1962 |
| The Cuminin Station Co. | - | Cuminin, Doodlakine | 1CC | 1912 |
| The DeGrey River Pastoral Co., Ltd | - | DeGrey Station, Port Hedland | 5MR | 1926 |
| The Executor | (G.F. Scott) late John Scott | Donelly, Elgin | SSJ | 1912 |
| The Griffin Coal Mining Company Ltd. | - | Bunker Bay, Dunsborough via Busselton | 0GR and 35B, 31A | 1962 |
| The Hill River Pastoral Co. | - | Melbourne Locs. 3117, 2489, 2495, Margaret River | I1L and 119D, 24E | 1962 |
| The Marron Pastoral Co. | - | Marron Station, Carnarvon | 8NN and 34C, 58F | 1962 |
| The Native Mission Farm Roelands W.A. Inc. | - | Native Mission Farm, Roelands | NN5 and 45B, 119A | 1962 |
| The New Zealand & Australian Land Co. Ltd. | - | Tootra, Moora, Beringarra, Upper Murchison | ZL0 | 1912 |
| The Oaks Syndicate | - | The Oaks, Warren Road, Katanning | OS6 | 1912 |
| The Pious Society of Missions | - | St. Joseph's Farm, Loc. 8677, Tardun | P8M and 5B, 46A | 1962 |
| The Pious Society of Missions Inc. | - | Pallotine Mission, Via Halls Creek | 3JM and 103D,6E | 1962 |
| The Redhill Firewood & Timber Co. | - | Onga Park, Ongerup | 3OP and 33B, 19A | 1962 |
| The Roman Catholic Vicar Apostolic of the Kimberleys | - | Thangoo Station South, Broome | L6L and 115B, 115A | 1962 |
| The W.A. Goldfields F.S Coy | - | Jaurdie Hills, Kurrawang | 0FS | 1912 |
| The West Australian Trotting Association Inc. | - | Nelson Crescent, East Perth | WA0 | 1962 |
| The Westralian Farmers Limited | - | 569 Wellington Street, Perth | 6WF | 1926 |
| Thelemann | Fred. | Port Hedland | 1FT | 1924 |
| Thelemann, | Fred | Port Hedland | 1FT | 1912 |
| Thesiger | E. & M. V. | Ingleside Farm, Gingin | S8E and 5B, 37A | 1962 |
| Thesiger | E. T. | 1 Mile Farm, Dowerin | D4T and 11B, 80A | 1962 |
| Theyer | Edgar J. | Crippets, Gordon River | T3G | 1924 |
| Thick | L. G. | Loc. 5262, Mt. Barker | MT9 | 1962 |
| Thick | L. M | Knungjen, Merredin | MT9 | 1912 |
| Thick | L. M. | Knungjen, Merredin | MT9 | 1924 |
| Thick | Thomas | Barrambie, Barrambie | TT9 | 1912 |
| Thick | Thos. | Barrambie, Barrambie | TT9 | 1924 |
| Thiel | Estate of P. H. W. | Struan, Yelbeni | 7HT and 7B, 7A | 1962 |
| Thiel | G. C., T. W. H. & H. E. | Struan, Yorkrakine | 7HT | 1924 |
| Thiel | G.C, P.W.H. & H.E. | Struan, Yorkakine | 7HT | 1912 |
| Thiel | Herman | Mt. Brown, P.O. Fremantle | 4HT | 1912 |
| Thiel | Hermann | Mt. Brown, P.O., Fremantle | 4HT | 1924 |
| Thiel | L. F. | Locs. 9746, 13752, 11071, Lake Grace | 4FT and 50B, 28E | 1962 |
| Thiele | J. C. | Avon Loc. 25154, Muntadgin | 8JT and 8B, 105A | 1962 |
| Tholsbrup and Christensen | S. & J. C. | Dandagin Loc. 10337, Kulin | QC4 | 1924 |
| Tholstrup | J. E. | Dandagin, Kulin | 2ST and 55F, 34B | 1962 |
| Thom | A. P. | Wydgee, Mt. Magnet | T3W | 1924 |
| Thom | C. R. | Lake Kwornicup and Greenrange, Lake Kwornicup | C6T and 112B, 18A | 1962 |
| Thomas | G. H. | Moonyoonooka, Geraldton | TH9 | 1924 |
| Thomas | A. A. A. | Ravenswood, Pinjarra | A6T | 1924 |
