| Osborne | W. O. | 168 Albany Road, Victoria park | Chevrolet | 4413 | Metro Private Car | 1923-24 |
| Osborne | W. O. | 300 Albany Road, Victoria Park | Chevrolet | 4413 | Metro Private Car | 1925-26 |
| Osborne | W. O. | 300 Albany Road, Victoria Park | Chevrolet | 4413 | Metro Private Car | 1926-27 |
| Osborne | W. O. | 300 Albany Road, Victoria Park | Chevrolet | 4413 | Metro Private Car | 1927-28 |
| Osborne Co | S. P. | Goodrich Tyre Co | Essex | 965 | Metro Private Car | 1926-27 |
| Osbourne | A. | Allanson | Cleveland | CO ● 121 | Collie Road Board | 1927-28 |
| Osbourne | E. C. | 18 Kershaw Street, Subiaco | Studebaker | 1232 | Metro Private Car | 1922-23 |
| Osbourne | J. | Bruce Rock | Dodge | BK ● 16 | Bruce Rock Road Board | 1922-23 |
| Osbourne | S. P. | Jubilee Street, South Perth | Ford | 7823 | Metro Private Car | 1925-26 |
| Osbourne | Stanley P. | 41 Clifton Crescent, Mount Lawley | Essex | 965 | Metro Private Car | 1927-28 |
| Osbourne | W. H. | Bruce Rock | Essex | BK 11 | Bruce Rock Road Board | 1923 - 1924 |
| Osbourne | W. O. | Albany Road, Victoria Park | Flanders 20 H.P. | P 1084 | Perth Municipality | 1917-18 |
| Osbourne | W. O. | 300 Albany Road, Victoria Park | Chevrolet | 4413 | Metro Private Car | 1924-25 |
| Osbourne | Wm. O. | 168 Albany Road, Victoria Park | Flanders | 1377 | Metro Private Car | 1922-23 |
| Osterberg & Campbell | - | Trayning | Ford Truck | KTY ● 25 | Kununoppin-Trayning Road Board | 1927-28 |
| Ostle | T. | Wanneroo | Rugby | WN ● 29 | Wanneroo Road Board | 1926-27 |
| Ostle | T. | Wanneroo | Rugby | WN ● 29 | Wanneroo Road Board | 1927-28 |
| Oterberg & Campbell | - | 30 Collie Street, Fremantle | Ford Truck | 3982 | Metro Hire or Trade | 1926-27 |
| Otfer | M. G. | Colin Street, West Perth | Nash | 5031 | Metro Private Car | 1927-28 |
| OToole | M. J. | 168 Hay Street | Car | S 44 | Subiaco Municipality | 1917-18 |
| Ottaway | A. E. | Wyalkatchem | Chrysler | WM ● 188 | Wyalkatchem Road Board | 1926-27 |
| Ottaway | A. E. | Wyalkatchem | Chrysler | WM ● 188 | Wyalkatchem Road Board | 1927-28 |
| Ottaway | J. F. | 20 Mann Street, Cottesloe | Swift | 6266 | Metro Private Car | 1927-28 |
| Ottaway | J. F. | 20 Mann Street, Cottesloe | Morris Cowley | 7682 | Metro Private Car | 1927-28 |
| Ottaway | K. A. | Bedfordale | Ford Truck | A-K ● 70 | Armadale-Kelmscott Road Board | 1924-25 |
| Ottaway | K. A. | Bedfordale | Ford Truck | A-K ● 70 | Armadale-Kelmscott Road Board | 1925-26 |
| Ottaway | K. A. | Bedfordale | Ford Truck | A-K ● 70 | Armadale-Kelmscott Road Board | 1926-27 |
| Ottaway | K. A. | Bedfordale | Ford Truck | A-K ● 70 | Armadale-Kelmscott Road Board | 1927-28 |
| Ottaway | T. A. | Hopetoun Street, South Perth | Whippet | 14059 | Metro Private Car | 1926-27 |
| Ottaway | T. A. | Hopetoun Street, South Perth | Whippet | 14059 | Metro Private Car | 1927-28 |
| Ottery | S. J. | Linden | Napier 16-20 H.P. | ML 2 | Mount Malcolm Road Board | 1916 |
| Ottery | S. J. | Linden | Napier 16-20 H.P. | ML ● 11 | Leonora-Malcolm Road Board | 1917-18 |
| Ottery | S. J. | Linden | Napier 16 H.P. | ML 11 | Leonora-Malcolm Road Board | 1919 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1922-23 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1923-24 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1924-25 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1925-26 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1926-27 |
| Ottery | S. J. | Leonora | Ford | LM ● 14 | Leonora-Malcolm Road Board | 1927-28 |
| Ottewell | B. | 59 Broadway, Nedlands | Dodge | 6560 | Metro Private Car | 1925-26 |
| Ottewell | B. | 59 Broadway, Nedlands | Dodge | 6560 | Metro Private Car | 1927-28 |
| Ottewell | H. | 59 Broadway, Nedlands | Dodge | 6560 | Metro Private Car | 1924-25 |
| Ottey | C. | 101 Douro Road, South Fremantle | Ford Truck | 10918 | Metro Hire or Trade | 1927-28 |
| Ottey | Mrs L. | Shaftesbury Hotel, Perth | Morris-Cowley | 5747 | Metro Private Car | 1924-25 |
| Otto | P. B. | 48 King George Street, Victoria Park | Overland | 1403 | Metro Private Car | 1922-23 |
| Otto | P. B. | 48 King George Street, Victoria Park | Overland | 1403 | Metro Private Car | 1923-24 |
| Ottway | C. | Merredin | Chevrolet | MD ● 160 | Merredin Road Board | 1927-28 |
| Ottway | W. | Cunderdin | Ford | ME ● 23 | Meckering Road Board | 1923-24 |
| Ottway | W. | Cunderdin | Ford | ME ● 23 | Meckering Road Board | 1924-25 |
| Ottway | W. | Cunderdin | Ford | ME ● 23 | Meckering Road Board | 1926-27 |
