| Seaton | I. | Cimbrone Stud, Maida Vale | C1M | 1962 |
| Seaton & Egan | A. & J. F. | The Commons, Hall's Creek | Y1A | 1924 |
| Seaton Ross Pastoral Co. | - | Seaton Ross, Yericoin | SR9 and 32D, 42E | 1962 |
| Sebbes | J. A. | Gascoyne, Sussex 2704, Forest Grove | SJ8 and 7C, 50E | 1962 |
| Sebbes | Wm. | Roebourne | 7YY | 1924 |
| Seber | Fritz | Connmonage, Kojanup | 7SF | 1912 |
| Seber | Fritz | Kojonup | 7SF | 1924 |
| Secker | D. A. J. | Riverdale, Boyup Brook | D4S and 12B, 111A | 1962 |
| Secker | Francis M. | Kentbury, Bullaring | YV0 | 1925 |
| Secombe & Co. | - | Mowla Station, Derby | T3Y | 1928 |
| Secome & Murphy | - | Broome | XN2 | 1924 |
| Secretan | R. C. | Crustal Brook and Loc. No. 5727, Narrikup | RS1 and 32C, 20E | 1962 |
| Seddon | J. | Dunwandring, Williams | SJ0 and 8B, 8E | 1962 |
| Seddon | Wm. | Gosnells Road, Gosnells | 6ZW | 1924 |
| Sedery | Chas. | Caringa Farm, Boyerine | 5SC | 1912 |
| Sedery | Chas. | Caringa Farm, Boyerine | 5SC | 1924 |
| Sedgman | M. I. & R. C. | Paradise Valley, Thompson's Brook | R9C and 5B, 15A | 1962 |
| Sedgwick | E. A. | Alawa Farm, Bruce Rock | 8EZ and 43B, 45A | 1962 |
| Sedgwick | E. J. F. | Melverley, Babakin | D5F and 12C, 46E | 1962 |
| Sedgwick | Edwin A. | Alawa Farm, Bruce Rock | 8EZ | 1924 |
| Sedgwick | Jane | Block 48/4148, Waroona | S6K | 1912 |
| Sedgwick | Jane | Block48/4148, Waroona | S6K | 1924 |
| See | Geo. | Mallebelling, York | G3S | 1912 |
| See | Geo. | Malebelling, York | G3S | 1924 |
| See | Geo. A. | HIllcrest, Newcarnie | 2ZY | 1924 |
| Seeber | D. D. | Roses Way, Boyup Brook | CB4 and 48B, 47A | 1962 |
| Seed | M. B. | Waikerie, Beverley | 7ON and 14B, 111A | 1962 |
| Seeley | N. R. G. | Kooyong, Gnowangerup | S2N and 32C, 23E | 1962 |
| Seery & Stacey | - | Block No. 10690, Jinarin, East Wagin | Y3Y | 1924 |
| Segenfredo | B. | Nelson Loc. 5959, Glenoran, via Manjimup | BS4 | 1962 |
| Seidel | F. A. | Block 872, Kendenup | 6FZ and 58F, 37C | 1962 |
| Seidel | Fredk. A. | Verndale, Mortigallup | 6FZ | 1924 |
| Seigert | M. F. & E. F. | Cacoola, Bullaring | SD4 and 43C, 34E | 1962 |
| Seimons | G. W. | Blocks 10295/74, 20240/55, South Kunjinn | 6SW | 1912 |
| Seimons | G. W. | 10295/74 and 20240/55, South Kunjinn | 6SW | 1924 |
| Seinor | Saml. | Morbelling, Tammin | SR7 | 1912 |
| Seinor | Samuel | Morbelling, Tammin | SR7 | 1924 |
| Seinor | Samuel C. | Cromwell Farm, Tammin | 1YS | 1924 |
| Seivwright | C. & D. | Mt. Farmer Station and Glen Station, Mt. Magnet and Cue | ZR9 and 14C, 15A | 1962 |
| Seivwright | Charles | c/o Crooks & Brooker, Ltd., Cue | ZR9 | 1924 |
| Seivwright | Mrs M. | Ayr Valley, Narra Tarra | MS6 | 1924 |
| Seivwright | Mrs. M. | Ayr Valley, Narra Tarra | MS6 | 1912 |
| Selanders | Willie P. | Hall's Creek | YL8 | 1924 |
| Seldon | H. A. | Alsworthy Farm, Pingarning, East Wagin | 8SL | 1912 |
| Seldon | H. A. | Alsworthy Farm, Pingarning, East Wagin | 8SL | 1924 |
| Selkirk | D. | Marrinup | 5SD | 1924 |
| Selkirk | Robt. | Beenup, Beenup | R4S | 1912 |
| Selkirk | Robt. | Byford | R4S | 1924 |
| Sellan | Wm. | Itinerary, Hall's Creek | V7S | 1924 |
| Sellar Bros. | - | Rose Hill, Kirk's Rock | SQ2 | 1924 |
