The innovative format of the match will see all three teams face each other on October 14, at Suva’s ANZ Stadium.
Fiji will face PNG before Australia takes on both PNG and finally Fiji. All three match-ups will last 40 minutes.
It will be the Kangaroos' first match in Fiji.
"This is a wonderful initiative and will be an historic day for Fiji, who will be hosting not one but two nations," NRL head of football Brian Canavan said.
"Fiji will get to see some of the best players in the world.
"Clearly the other important aspect will be that each contest will provide a strong preparation for the 2017 Rugby League World Cup." Kangaroos coach Mal Meninga said the contest would be a novel way to prepare for his team, as well as an important one.
"Not only will this contest be good for the Kangaroos' preparation for the World Cup, it will be wonderful for international rugby league," Meninga said.
"I love the concept of three teams playing on the same stage. It will be a great exhibition for our game."
Fiji Bati coach Mick Potter said: "It will be a great showpiece. It can only be a good thing for the game in Fiji for the locals to see the Australian team playing against two different nations, including their own.
"The people of Fiji will appreciate having all the names associated with this Kangaroos team at their stadium, as well as the best players in Fiji and PNG. To have that calibre of player on show will be phenomenal for the game."
PNG coach Michael Marum said: "It’s the first time this has ever happened so it will be a good experience for all of us.
"We’ll take a lot out of playing 40 minutes of football against each of those teams, and we’re looking forward to doing some community work alongside Fiji as they work to make rugby league even stronger over there."