| 4th/19th Prince of Wales's Light Horse Regiment | |
|---|---|
 Cap badge of the 4th/19th Prince of Wales's Light Horse | |
| Active | 1948 – present |
| Country |  Australia |
| Branch | Army Reserve |
| Type | Light horse |
| Role | Light cavalry |
| Size | One regiment |
| Part of | 4th Brigade |
| Garrison/HQ | Simpson Barracks |
| Motto(s) | Ich Dien (I Serve) |
| Colours | Red, white |
| March | Australian Light Horse |
| Engagements | Vietnam War |
| Commanders | |
| Current commander | Lieutenant Colonel Duncan Munro |
| Colonel-in-Chief | King Charles III (Colonel-in-Chief, RAAC) |
| Insignia | |
| Unit colour patch |  |
The 4th/19th Prince of Wales's Light Horse (4/19 PWLH) is a cavalry regiment of the Australian Army. The regiment in its current composition was formed in 1948, when the Citizens Military Force (CMF) was re-raised after the completion of the demobilisation process following the end of the Second World War, through the amalgamation of three previously existing regiments. Through these predecessor units, 4/19 PWLH can trace its lineage back to the 19th century and today it is the custodian of the battle honours earned by these units. The regiment had a Regular squadron, 1 Troop 4th/19th Prince of Wales Light Horse Regiment, which was posted to South Vietnam in 1965 where it was attached to 1 RAR operating out of Bien Hoa Province. It returned to Australia on 28 May 1966 and became part of the Regular cavalry units that continue to exist in the Australian Army today. These units subsequently served during the Vietnam War and many of their personnel continued to wear regimental accoutrements while in South Vietnam.
Today 4/19 Prince of Wales Light Horse Regiment is an Australian Army Reserve regiment and forms part of the 4th Brigade, 2nd Division based in Victoria. As part of the restructure of the Royal Australian Armoured Corps (RAAC) units of the Australian Army Reserve it is now equipped with Bushmaster Protected Mobility Vehicles.