| Sinclair | B. | 5852, 6060, Napier, Albany | 5SB and 20B, 113E | 1962 |
| Sinclair | Eliz. | Egoline, Northam | 1ES | 1924 |
| Sinclair | Eliza J. | Egoline, Northam | 1ES | 1912 |
| Sinclair | Ernest James | Myrup Farm, Esperance | EZ8 | 1924 |
| Sinclair | Fredk. Wm. | Cockburn Sound Loc. 92, East Rockingham | 2QP | 1924 |
| Sinclair | G. E. | Nolacatting, Wongan Hills | 4ES | 1912 |
| Sinclair | G. E. | Nolcatting, Wongan Hills | 4ES | 1924 |
| Sinclair | G. E. | Caithness, Kondut | 4ES and 80D, 21E | 1962 |
| Sinclair | G. G. | Avon Loc. 1953, Toodyay | ZG6 | 1924 |
| Sinclair | G. G. | Rose Valley, Toodyay | ZG6 and 10C, 34E | 1962 |
| Sinclair | George T. | Roe Loc. 78, Newdegate | G1S | 1927 |
| Sinclair | Isabella F. | 62 Mandurah Road, South Fremantle | 7SN | 1912 |
| Sinclair | Isabella F. | 62 Mandurah Road, South Fremantle | 7SN | 1924 |
| Sinclair | J. & J. H. | Yugildah Farm, Malyalling | US5 | 1924 |
| Sinclair | J. S. | Newcalbeon via Dowerin | O1J | 1912 |
| Sinclair | J. S. | Newcalbeon, via Dowerin | O1J | 1924 |
| Sinclair | Laura | Nine-Mile Hill, Toodyay | LF7 | 1912 |
| Sinclair | Laura | Nine Mile Hill, Toodyay | LF7 | 1924 |
| Sinclair | Laurence jun. | Esperance | LS3 | 1912 |
| Sinclair | Laurence, jun. | Esperance | LS3 | 1924 |
| Sinclair | Leslie M. | Hillock Farm, Esperance | Z3N | 1924 |
| Sinclair | Matthew J. | Mardajong, Wuraming | MS3 | 1926 |
| Sinclair | Olive | Carinyia, East Rockingham | 4OZ | 1924 |
| Sinclair | P. | Portion M.1576, Three Springs | P2L and 3B, 50A | 1962 |
| Sinclair | R. G. | Merriton, M.1576 pt., Three springs | SX7 and 18D, 117E | 1962 |
| Sinclair | S. F. | New York, Toodyay | 1SS and 9B, 27A | 1962 |
| Sinclair | S. S. | Leatherhead, Toodyay | LF7 and 109B, 5A | 1962 |
| Sinclair | Samuel W. | Northam Sub. Lots N72, N70, and N68, Mervyn Street, Northam | 7KQ | 1925 |
| Sinclair | Stewart F. | New York, Toodyay | 1SS | 1927 |
| Sinclair | Wm. Arthur | Ten-ten Farm, Ninghan | 9SN | 1924 |
| Sinclair Bros. | - | Blocks 1899, 1898, 4899, Dalwallinu | T4S | 1912 |
| Sinclair Bros. | - | 1899-98 and 4899, Dalwallinu | T4S | 1924 |
| Sing | Mrs J. A. | Rosadale Farm, Midland Junction | Z5J | 1924 |
| Sing-Quan | K. | Gascoyne 185, Toodyay | K9N | 1962 |
| Singh | Athoo | S. Cunderdin | S9O | 1924 |
| Singh | Kininga & Bagga | Avon Location 8830, Cunderdin | 1KS | 1912 |
| Single | Harry E. | Eden Garden, Day Dawn | 1SN | 1924 |
| Singleton | E. | Lees Hall, Jandakot | SN7 | 1962 |
| Singleton | E. & L. | Nelson loc. 5261 | 5EL | 1962 |
| Singleton | L. A. | Loc. No. Victoria 9964, Carnamah | 5SZ and 41B, 12A | 1962 |
| Singleton | L. S. | Merrilees Farm, Busselton | S9N and 40B, 6A | 1962 |
| Sinnott | E. J. | Bourneville, Boyup Brook | 1XT and 55F, 21D | 1962 |
| Sinnott | Eliz. E. | Bellagnp, Bridgetown | 0ES | 1924 |
| Sinnott | Eliz. H. | Bellagup, Bridgetown | 0ES | 1912 |
| Sippe | N. S. & W. A. | Queereiding Springs, Bruce Rock | N2W and 4D, 104E | 1962 |
| Sippe | S. R. T. & A. D. | Wattle Hill, Bruce Rock | 1XS and 42B, 28A | 1962 |
| Sippe | Stephen G. | Kulbulliken, Bruce Rock | 1XS | 1924 |
| Sirmon | John | Water Karry, York | PS3 | 1912 |
| Sirmon | John | Water Karry, York | PS3 | 1924 |
| Sisson & Horn | - | Yilgarn Loc. 634, Wetheral, Bodalling | S2H | 1926 |
