| Mengler | Gus. | Goldsworthy Road, Claremont | Studebaker | 2423 | Metro Private Car | 1925-26 |
| Mercer | H. K. | 85 Rokeby Road, Subiaco | Overland | 1264 | Metro Private Car | 1927-28 |
| Merchant | T. | Kellerberrin | Ford | KE ● 24 | Kellerberrin Road Board | 1922-23 |
| Meredith | E J. | Lake Grace | Rugby | LG ● 135 | Lake Grace Road Board | 1927-28 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1925-26 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1926-27 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1927-28 |
| Mereer | C. L. | Holyoake | Amphion | MY ● 51 | Murray Road Board | 1922-23 |
| Merfield & Holmes | - | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1917-18 |
| Merfield & Homes | - | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1919 |
| Merifield | T. S. | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1916 |
| Merredin Co-op. | - | Merredin | Studebaker | MD ● 97 | Merredin Road Board | 1924-25 |
| Merriden Co-op. | - | Merriden | Studebaker | MD ● 97 | Merredin Road Board | 1925-26 |
| Merritt | J. E. | 17 Keightly Road, Subiaco | Willys-Knight | 9164 | Metro Private Car | 1925-26 |
| Merritt | J. E. | 17 Keightly Road, Subiaco | Willys-Knight | 9164 | Metro Private Car | 1926-27 |
| Merritt | J. E. | 17 Keightly Road, Subiaco | Willys-Knight | 9164 | Metro Private Car | 1927-28 |
| Mertield & Holmes | - | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1922-23 |
| Metske | A. | Darlot | Ford Truck | LA ● 10 | Lawlers Road Board | 1926-27 |
| Metske | Thos. | Wiluna | Dodge | WU ● 22 | Wiluna Road Board | 1926-27 |
| Metske | Thos. | Wiluna | Dodge | WU ● 22 | Wiluna Road Board | 1927-28 |
| Mettam | A. W. | Quelagetting | Ford Truck | ME ● 147 | Meckering Road Board | 1926-27 |
| Mettam | A. W. | Quelagetting | Ford Truck | ME ● 147 | Meckering Road Board | 1927-28 |
| Mettam | W. D. | Quelagetting | Ford Truck | ME ● 147 | Meckering Road Board | 1925-26 |
| Metters Ltd | - | 762 Hay Street, Perth | Studebaker | 1124 | Metro Private Car | 1922-23 |
| Metters Ltd | - | Hay Street, Perth | Studebaker | 1124 | Metro Private Car | 1923-24 |
| Metters Ltd | - | Hay Street, Perth | Studebaker | 14864 | Metro Private Car | 1927-28 |
| Metzke | A. | - | Ford 15 H.P. | LA ● 14 | Lawlers Road Board | 1917-18 |
| Metzke | A. | Darlot | Ford | LA ● 10 | Lawlers Road Board | 1923-24 |
| Metzke | A. | Darlot | Ford | LA ● 10 | Lawlers Road Board | 1924-25 |
| Metzke | A. | Darlot | Ford | LA ● 10 | Lawlers Road Board | 1925-26 |
| Metzke | A. | Darlot | Ford | LA ● 10 | Lawlers Road Board | 1927-28 |
| Mews | J. W. | Ulster Road, Albany | Studebaker 25 H.P. | A 3 | Albany Municipality | 1919 |
| Meyer | Mrs K. M. | 23 Kent Street, Victoria Park | Ford Wagon | 10155 | Metro Hire or Trade | 1927-28 |
| Meyn | R. C. | Nyabing | Overland | KT ● 3 | Kent Road Board | 1925-26 |
| Meyn | R. C. | Nyabing | Overland | KT ● 3 | Kent Road Board | 1926-27 |
| Meyn | R. C. | Nyabing | Overland | KT ● 51 | Kent Road Board | 1926-27 |
| Meyn | R. C. | Nyabing | Overland | KT ● 51 | Kent Road Board | 1927-28 |
| Meyne | R. C. | Nyabing | Overland | KT ● 3 | Kent Road Board | 1924-25 |
| Miles | C. A | Albany Road, Kenwick | Ford | 2853 | Metro Private Car | 1927-28 |
| Miles | H. E. | Albany | Studebaker 20 H.P. | A 73 | Albany Municipality | 1919 |
| Miles | Mrs | Cookernup | Ford | H ● 159 | Harvey Road Board | 1926-27 |
| Miles | Mrs | Cookernup | Ford | H ● 159 | Harvey Road Board | 1927-28 |
| Millard | J. | - | Studebaker 25 H.P. | GN 26 | Geraldton Municipality | 1915 |
| Millard | J. | Geraldton | Studebaker 25 H.P. | GN 26 | Geraldton Municipality | 1916 |
| Millard | J. | Cnr. Lake & Bulwer streets, Perth | Dodge | 9382 | Metro Private Car | 1926-27 |
| Millard | John W. | Lake & Bulwer streets, Perth | Morris-Cowley | 1973 | Metro Private Car | 1927-28 |
| Millars | L. G. | Narrogin | Studbaker | NGN 54 | Narrogin Municipality | 1923-24 |
| Millbank | C. H. | 17 Bay View Mansions | Studebaker | 9098 | Metro Private Car | 1925-26 |
| Millbank | C. H. | 17 Bay View Mansions | Studebaker | 9098 | Metro Private Car | 1926-27 |
| Millbank | C. H. | 17 Bay View Mansions | Studebaker | 9098 | Metro Private Car | 1927-28 |
