| Plumb | George Forster | Avon Locs. 23635, 32479, 23480, South Kuminin | G5P | 1926 |
| Plummer | Clifford | Lot 30 of Canning Loc. 31, Kelmscott | 9PC | 1912 |
| Plummer | Clifford | Cooraminta, Tenindewa | 9PC | 1924 |
| Plummer | John | Cooraminta, Tenindewa | PJ5 | 1912 |
| Plummer | John | Mervyndale, Yorkrakine | PJ5 | 1924 |
| Plummer | John Robert | c/o S. Gray, Warren River, Jardanup | O3Q | 1925 |
| Plummer & Gurr | - | Mervyndale, Yorkrakine | P2G | 1912 |
| Plummer & Gurr | - | Avon Locs. 11748, 11746, 11745, 11747, Korrelocking | P2G | 1924 |
| Plunkett | B. W. | Fitzgerald Loc. 620-3, Circle Valley | BP4 and 46B, 32E | 1962 |
| Plunkett | Chas. | Williams Loc. 10591, Merilup, E. Wagin | 7PU | 1924 |
| Plunkett | M. G. | Locs. 536, 634-5, Australind | 7GP | 1962 |
| Pluschke | D. | Victoria Loc. 9942, Northampton | JV0 and 23D, 31E | 1962 |
| Pluschke | D. H. & W. E. | 100-147, Northampton | DP7 and 27B, 119E | 1962 |
| Pluschke & Sons | J. F. H. | Victoria Loc. 6945, Yarra Northampton | 4JP and 42C, 104E | 1962 |
| Plyale | G. | Amphion Farm, Amphion | XN6 | 1924 |
| Poad | Edwin | Stenelles, Dardanup | 7PD | 1924 |
| Poad | Edwin P. | Avon Locs. 11748, 11746, 11745, 11747, Korrelocking, Dowerin | 7PD | 1912 |
| Poad | L. R. | Riverlynn, Armadale | 7PD and 8D, 119E | 1962 |
| Poad | Lewis A. | Dardanup | 5VP | 1925 |
| Poad & Sons | W. V. | Glenbrook, Dardanup | 5VP and 47B, 41A | 1962 |
| Pobjoy | H. C. | Booninig, Darkan | BC5 | 1924 |
| Pocock | Bernard | Somerhill, Needilup, via Ongerup | P5P | 1924 |
| Pocock | C. R. | Maranup Farm, Bridgetown | PR9 | 1962 |
| Pocock | Fanny | Somerhill, Needilup, via Ongerup | 8PF | 1924 |
| Pocock | S. J. | Somerhill, Needilup, Via Ongerup | 8PF and 22C, 12E | 1962 |
| Podger | Chas. | Lucy Lynn Dairy, Meritta Road, Claremont | R4N | 1924 |
| Podger | George | Glenview, Kelmscott | 5QP | 1925 |
| Podmore | R. M. & R. J. | Leaswood, Cadoux | P2R and 42D, 22E | 1962 |
| Podmore Bros. | - | Marney Vale Farm, Kellerberrin South | 0PZ | 1924 |
| Poett | A. W. | Kobeelya Ave Katanning | 7AP and 36B, 5E | 1962 |
| Poett | E. H. | Mortigallup, Via Kendenup | E1P and 102C, 59F | 1962 |
| Poett | H. F. | 299, 376, 298, 296-7, 349, 261, 214-5-7, Katanning | H5P and 59F, 49D | 1962 |
| Poett | T. T. | Kooringa, Katanning | 2TP and 2C, 25E | 1962 |
| Poett | Wm. H. | Stenelles, Dardanup | 1PW | 1912 |
| Poett | Wm. H. | Oakley, Tambellup | 1PW | 1924 |
| Poett & Co. | F. H. | Greystone Katanning | FP8 and 32B, 18A | 1962 |
| Pohlner | F. W. | Frome Downs, Bencubbin | F3P and 47B, 43A | 1962 |
| Pohlner | T. J. | Yourmead, Cranbrook | TP2 and 14C, 13B | 1962 |
| Pola | Carnalao | Rusellina Farm, Bulading Siding | UP0 | 1924 |
| Poland, | F. F. | Yargalain, Wannamal | FP7 and 29D, 14E | 1962 |
| Polelle Pastoral Co. | - | Polelli Station, Nannine | 3ZX and 44C, 29A. | 1962 |
| Poletti | R. | Oakley, Tambellup | 8PR | 1912 |
| Poletti | R. | Terono, Tambellup | 9PR | 1924 |
| Polhtt | J. & P. | Fairbairn, Wooroloo | P0L and 115B, 27A | 1962 |
| Polhtt | J. K. | 74, Bassendean | 0KP | 1962 |
| Polinelli Bros. | - | Loc. M.1252, Chittering, Via Muchea | PM8 and 102C, 54F | 1962 |
| Polkingham & Yuill | F. L. & C. H. | Yilgarn Locs. 149, 150, Westonia | Q5E | 1924 |
| Polkinghorn | A. S. | Avon 13502, 14660, Tubuk, Via Brookton | 2AP | 1962 |
| Polkinghorn | D. A. | Vinegar Hill, Jubuk, Via Corrigin | DP4 and 44B, 41E | 1962 |
| Polkinghorn | I. G. | Wundowlin, Welbungin | 9LP and 48B, 19E | 1962 |
