Tuttle named Australia U20 captain
Maclean Jones and Mack Mason were also in the running, but Australian coaches and selectors inaugurated Tuttle with the captaincy title.
The young Australians will travel to Manchester in preparation for their first match on June 8 against Scotland.
Coach Adrian Thompson has also made two changes to the squad with Joey Fittock and Harley Fox suffering injuries. They will be replaced by Liam McNamara and Ikapote Tupai respectively.
Thompson commented on his newly selected captain: "We are very lucky to be served by a strong leadership group in 2016 lead by James, Maclean and Mack.
"We have worked hard at our camp in Sydney and with an extra two wins under our belt there are good signs for our side.
"We need to build on that preparation and work even harder now otherwise it will all mean nothing. The team is very much looking forward to getting to Manchester and performing in a way that makes their country proud," he stated.
Australia Under-20 fixtures for the World Rugby Championship:
June 8, Australia v Scotland Kick-off: 2.30 AEST
June 11, Australia v Italy, Kick-off: 22.30 AEST
June 16, Australia v England, Kick-off: 4.45 AEST
Australia Under-20:
Forwards: Faalelei Sione (Brumbies)Tyrel Lomax (Brumbies, Vunipola Fifita (NSW Gen Blue), Ryan McCauley (NSW Gen Blue, Shambeckler Vui (Western Force), Josh Taylor (Queensland Reds, Richie Asiata (Queensland Reds), Lukhan Tui (Queensland), Harry Hocking (Queensland), Maclean Jones (Queensland), Angus Scott-Young (Queensland Reds), Izack Rodda (Queensland Reds), Liam Wright (Queensland), Jordan Uelese (Melbourne Rebels), Rob Leota (Melbourne Rebels), Ikapote Tupai (Melbourne Rebels.
Backs: Nick Jooste (Brumbies), Jordan Jackson-Hope (Brumbies), Simon Kennewell (NSW Gen Blue), Jack Maddocks (NSW Gen Blue), James Tuttle (Queensland Reds), Harry Nucifora (Queensland Reds), Mack Mason (Queensland Reds), Campbell Magnay (Queensland Reds), Liam Jurd (Queensland Reds), Sione Tuipulotu (Melbourne Rebels), Liam McNamara (Queensland), Ah-Mu Tuimalealiifano (Melbourne Rebels).