Among the inclusions in the expanded squad - which will be cut to 27 ahead of the farewell friendly with South Africa - was Preston North End defender Bailey Wright, 21.
He will be in the mix to replace axed former Socceroos skipper Lucas Neill, dropped by Postecoglou after the double-World Cup veteran struggled to get game time with clubs in the UK, or slot into the problem leftback role for the Roos.
Elsewhere in the side, Postecoglou selected established stars like Tim Cahill, Mile Jedinak, Dario Vidosic and Mark Milligan, alongside the high profile talented youngsters like Tom Rogic, Mat Ryan, Mathew Leckie and Matthew Spiranovic.
But rising A-League stars like James Troisi and Adam Taggart - who both had stunning seasons - are among 10 locally-based players who have also been selected for the youthful squad as part of the Regeneration Ange revolution which has an average age of 25.5.
Surprise inclusions are both Mark Birighitti and Euegene Galekovic to bolter Mitch Langerak and Ryan in goals, and former Central Coast Mariner Alex Wilkinson brought back into the squad.
Former Spurs youth Massimo Luongo, 21 - now at Swindon Town - also gets a call up to compete for a place in midfield.
The squad will begin arriving in Australia tomorrow for a pre-World Cup Camp in Gosford and Sydney before flying to Brazil on May 28 where they will face defending Champions Spain, 2010 World Cup runners up the Netherlands and South American danger side Chile.
"We’re excited to announce the preliminary 30-man Socceroos squad for the World Cup," Postecoglou said. "We’ve selected a squad we believe will represent the people of Australia with pride on the biggest stage in world sport.
"The squad has been selected with form and fitness as key indicators as well as having one eye on the future. We face a formidable challenge in Brazil but it is also a big opportunity and we head to the World Cup with no barriers as we look to write a new chapter in our rich football history."
Postecoglou will trim the squad to 27 after the Socceroos play South Africa, presented by NAB, on Monday 26 May at ANZ Stadium in Sydney. The final 23-man squad will be named on 2 June.
"We’ve named 30 players for the camp and will leave Australia with 27 before cutting the squad to 23 before the first game but we want all 30 players and the staff to get a meaningful experience out of the camps and World Cup," Postecoglou said.
"We want the camp to be competitive to make sure the training intensity is as high as possible as players strive to make the final 23 squad but everyone is equally important as we also have one eye on the future."
The full squad is:-