| Australia 81–12 Canada |
(6 June 2008)
| Australia 91–7 Tonga |
(1 May 2019)
| Australia 12–69 New Zealand |
(10 July 2022)
|Appearances||7 (First in 2008)|
|Best result||Runners-up, 2010 and 2019|
The Junior Wallabies is the national under-20 team that represents Australia playing rugby union. The team has been competing at the annual World Rugby U20 Championship since it began in 2008, replacing the previously held under-19 and under-21 championships. The team also competes at the Oceania U20 Championship as of 2015.
Australia's highest finish at the World Rugby Under 20 Championship was as runner-up in 2010 and 2019. The team finished third in 2011 by beating France in the third place playoff, and fourth in 2009 after losing to South Africa 32–5 in the third place playoff.
The Junior Wallabies name was incorporated into the Australian under-20 crest prior to the 2018 season, but the name was also previously applied to several other teams in the history of Australian rugby. In the era of amateur rugby from the 1950s onwards, the Junior Wallabies team was selected from uncapped players (with no age restriction) to play against touring Test sides  or to represent Australia on goodwill tours to Asia and the Pacific. Media publications sometimes also used the name Junior Wallabies to refer to age-graded national teams such as the Australian under 19 side, Australian Schoolboys, and later the Australian under 20 team.
Summary for all under 20 matches at the World and Oceania championships up to and including the 2022 Oceania Championship:
|Match 1||34–16||New Zealand|
|Match 2||18–19||New Zealand|
No tournament in 2022.
|Round 3||12–69||New Zealand|
No competition due to impacts of the COVID-19 pandemic.
|Round 3||24–0||New Zealand|
|Pool match||18–27||New Zealand|
|5th place play-off||41–16||Argentina|
|Round 3||28–43||New Zealand|
|5th place play-off||17–24||Scotland|
|Round 3||6–43||New Zealand|
|5th place play-off||24–55||New Zealand|
|Round 1||10–30||New Zealand|
|Round 2||25–24||New Zealand|
|Pool match||13–46||South Africa|
|5th place play-off||28–23||Wales|
|Round 3||29–46||New Zealand|
IRB World Championships 2008 to 2014