| Sinclair Brothers | - | Farmer | Toodyay | 1879 | WA Almanack |
| Sinclair, Parsons & Mann | | Solicitors, Proctors & Notaries Public, Commissioners for Affidavits | Hannan Street, Kalgoorlie | 1897 | Witton's Directory |
| Sinclar | A. & H. | Farmers | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | G. | Farmer | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | J. | Farmer | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | James | Landowner | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | Jno. sen. | Store Asst | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | T. | Farmer | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sinclar | W. | Farmer | Newcastle & Toodyay District | 1884 | WA Almanack |
| Sincock | J. | Miner | Victoria District (Northampton) | 1884 | WA Almanack |
| Sincock | J. | Miner | Victoria District (Northampton) | 1886 | WA Almanack |
| Sincock | J. | Miner | Northampton | 1887 | WA Almanack |
| Sincock | J. | Miner | Northampton | 1888 | WA Almanack |
| Sincock | J. | Miner | Northampton | 1889 | WA Almanack |
| Sincock | Joseph | Miner | Victoria District (Northampton) | 1880 | WA Almanack |
| Sincock | Joseph | Miner | Victoria Districts (Northampton) | 1882 | WA Almanack |
| Sincock | Joseph. | Miner | Victoria District (Northampton) | 1881 | WA Almanack |
| Sing | Ah | | 71 King Street, Perth | 1897 | Witton's Directory |
| Singers & Farrah | | Grocers | James Street, Perth | 1897 | Witton's Directory |
| Sission | J. M. A. | Solicitor | Perth | 1889 | WA Almanack |
| Sisson | J. M. A. | Solicitor | Perth | 1888 | WA Almanack |
| Sisson | J. M. A. | Solicitor | Bunbury | 1888 | WA Almanack |
| Sisson | J. M. A. | Solicitor | Bunbury, Etc. | 1889 | WA Almanack |
| Sisters of St. Joseph | | | Northampton | 1897 | Witton's Directory |
| Sivewright | D. | Farmer | Geraldton | 1877 | Herald Almanack |
| Sivewright | D. | Farmer | Victoria District (Geraldton) | 1877 | WA Almanack |
| Sivewright | D. | Farmer | Victoria District - Geraldton | 1878 | Herald Almanack |
| Sivewright | D. | Farmer | Geraldton | 1879 | Herald Almanack |
| Sivewright | D. | Farmer | Geraldton | 1880 | Herald Almanack |
| Sivewright | D. | Farmer | Geraldton | 1881 | Herald Almanack |
| Sivewright | D. | Farmer | Geraldton | 1882 | Herald Almanack |
| Sivyer | H. | Photographer | Albany | 1882 | WA Almanack |
| Sivyer | Henry | Photographer | Albany | 1887 | WA Almanack |
| Sivyer | Henry | Photgrapher | Albany | 1888 | WA Almanack |
| Sivyer | Henry | Photographer | Albany | 1889 | WA Almanack |
| Sivyier | H. | Photographer | Albany | 1881 | WA Almanack |
| Skaif | W. | Clerk | Fremantle | 1875 | Herald Almanack |
| Skaif | W. | Clerk | Fremantle | 1875 | WA Almanack |
| Skaif | W. | Clerk | Fremantle | 1876 | Herald Almanack |
| Skaif | W. | Clerk | Fremantle | 1877 | Herald Almanack |
| Skaife | G. | Railway Department | Fremantle | 1884 | WA Almanack |
| Skaife | G. T. | Mechanic | Fremantle | 1881 | Herald Almanack |
| Skaife | G. T. | Mechanic | Fremantle | 1882 | Herald Almanack |
| Skaife | G. T. | Mechanic | Fremantle | 1884 | Herald Almanack |
| Skaife | G. T. | Mechanic | Fremantle | 1885 | Herald Almanack |
| Skaife | G.T. | Mechanic | Fremantle | 1883 | Herald Almanack |
| Skaife | Geo. | Fitter | Fremantle | 1886 | WA Almanack |
| Skaife | Geo. | Fitter | Fremantle | 1887 | WA Almanack |
| Skaife | Geo. | Fitter | Fremantle | 1888 | WA Almanack |
| Skaife | Geo. | Fitter | Fremantle | 1889 | WA Almanack |
