| 3rd Motor Brigade | |
|---|---|
| Active | 1921–1944 |
| Country |  Australia |
| Allegiance | Australian Crown |
| Branch | Australian Army |
| Type | Motor |
| Size | Brigade |
| Part of | 2nd Cavalry Division 2nd Australian Motor Division 1st Armoured Division 2nd Infantry Division III Corps |
| Insignia | |
| Colour Patch | &sq=Qlik&lang=&file=File:Headquarters_3rd_Light_Horse_Brigade.png){kind=small} |
The 3rd Motor Brigade was a formation of the Australian Army during the interwar years and early part of World War II. Initially raised in 1921 as the 3rd Cavalry Brigade in Victoria, it was a formation of the part-time Militia. It consisted of three light horse regiments, which were spread across several depots in regional Victoria. During World War II, the brigade was mobilised for defensive duties in December 1941 to defend against a possible invasion. In early 1942, it was converted into a motorised formation and was redesignated as the 3rd Motor Brigade. The brigade moved to Western Australia in late 1942 and remained there until August 1944 when it was disbanded without having seen combat.