| Sewell | W. C. | Wood Norton, via Kellerberrin | 8WU | 1924 |
| Sewell | W. O. | Mapelstead, Pingelly | 3OS | 1912 |
| Sewell | W. O. | Maplestead, Pingelly | 3OS | 1924 |
| Sewell & Co. | G. D. | Maplestead, Pingelly | 4GD and 42C, 18A | 1962 |
| Sewell & Co. | Q. M. | Stanhope, Wongan Hills | 1AS and 8B, 111A | 1962 |
| Sewell & Sons | H. | Plantagenet 38, 53, Lower Kalgan, Albany | SH4 and 52F, 41B | 1962 |
| Sewell Bros. | - | Caversham, Aldersyde | Z4O | 1924 |
| Sewell Bros. | - | Noombling, West Pingelly | S3E and 36B, 16A | 1962 |
| Sewell Grazing Co. | E. V. | Sand Springs, Geraldton | 3SS and 23B, 23A | 1962 |
| Sexton | A. I. | Sextorvale, Korrelocking | 9SX | 1924 |
| Sexton | A. J. & R. A. | Glenark, Cuballing | AS0 and 28D, 24E | 1962 |
| Sexton | A. R. | Bedford, Marradup | KK5 and 26B, 10A | 1962 |
| Sexton | Geo. | P.L. 929/96, Nallan via Cue | 6GS | 1912 |
| Sexton | Geo. | P/L 929/96, Nallan, via Cue | 6GS | 1924 |
| Sexton | Robt. | Belford Downs, Hall's Creek | BD7 | 1912 |
| Sexton | Robt. | Bedford Farm, Muradup | KK5 | 1924 |
| Sexton & Drysdale | - | Excelsior South Mills, Noggerup | SD9 | 1912 |
| Sexton & Drysdale | - | Excelsior, South Mile, Noggerup | SD9 | 1924 |
| Sexton & Gordon | - | Idamere Downs, East Kimberley | KG2 | 1912 |
| Sexton & Kelly | - | Belford Downs, Turkey Creek | LC5 | 1912 |
| Sexton & Kelly | - | Bedford Downs, Turkey Creek | LC5 | 1924 |
| Sexty | R. G. | Mills Road, Gosnells | T0V | 1924 |
| Seyed | Hoosane | Coolgardie | HS4 | 1912 |
| Seyed | Hoosane | Coolgardie | HS4 | 1924 |
| Seyfort | John D. | Fairview, Moorine Rock | G4T | 1927 |
| Seymour | A. G. | Dunsborough | A2L | 1912 |
| Seymour | A. L. & E. R. | Madgingarra, Miling | SY5 | 1962 |
| Seymour | A. T. | Nelson | RV4 | 1924 |
| Seymour | C. G. | Locs. 44-7 (536), Dunsborough | VS1 and 32D, 15E | 1962 |
| Seymour | E. R. | Madingarra, Miling | E6S and 34B, 3E | 1962 |
| Seymour | Frederick Chas. | Densbro, Quindalup | FS0 | 1912 |
| Seymour | Fredk. Chas. | Dunsbro', via Quindalup | FS0 | 1924 |
| Seymour | George | Onslow | 8GZ | 1924 |
| Seymour | H. | Cowalcarra, Moora | HS7 | 1912 |
| Seymour | H. | Cowalearra, Moora | HS7 | 1924 |
| Seymour | H. N. | Chatswood, Mt. Barker | SH6 and 19C, 108E | 1962 |
| Seymour | H. T. & A. M. | Meridale, Miling | TS6 and 35B, 5E | 1962 |
| Seymour | J. F. | 20, 46, 170, 277, Dunsborough | FS0 | 1962 |
| Seymour | Joshua W. | Greenmoors, Lake Biddy | JS6 | 1927 |
| Seymour | L. W. | Manji Springs, Miling | 8SE and 13D, 115E | 1962 |
| Seymour | M. | Woodbine, Miling | 9SG and 15B, 19A | 1962 |
| Seymour | Robt. J. | Sussex Location 47/44, Dansborough | VS1 | 1912 |
| Seymour | Robt. J. | Sussex Loc. 47/44, Dunsborough | VS1 | 1924 |
| Seymour | S. G. | Woodbine, Miling | HS7 and 16B, 14E | 1962 |
| Seymour | T. | Hillview, Moora | TS6 | 1912 |
| Seymour | T. | Hillview, Moora | TS6 | 1924 |
| Seymour & Sons | R. H. | Madgingarra, Miling | S4Y and 4D, 102E | 1962 |
| Sha | Jolm | Murrin Murrin | S8A | 1924 |
| Shackles & Sons | - | Allawah, Beverley | S2S and 3D, 53F | 1962 |
| Shackleton | A. L. | 3563 Plantagenet Wendover, Albany | 5AL and 115D, 33E | 1962 |
