Sir Barry, 78, died in Brisbane's Mater Hospital at about 1930 (AEDT) on Wednesday with his family members and former partner, Fua, present.
|Sir Barry Holloway|
A formidable politician, he first came to PNG as a Kiap, or provincial administrator, in 1953 at age 18.
"He fell in love with the place and its women," said Institute of National Affairs director Paul Barker, who was a friend of Sir Barry.
"He was dedicated and committed.
"He was a strong person for getting services out on the local level. He was a very caring man. As a Kiap, he never let it go to his head."
Sir Barry, along with Sir Michael and Tony Voutas went on to form the Pangu Pati in 1968 and he became speaker of the house of assembly in 1972.
When PNG gained full independence from Australia in 1975, he served as the nascent nation's first Speaker until 1977, before taking on the role of finance minister until 1982.
He ran for the governorship of the Eastern Highlands at the 2012 national election, narrowly losing to Julie Soso, one of the three women members of PNG's 111-member parliament.
Seven months before the election, he told AAP he was considering running again because he wanted to see more services delivered to the people.
Sir Michael Somare's spokeswoman, Betha Somare, said the former prime minister cherished Sir Barry's contribution to PNG and noted his contributions to legislative and constitutional amendments.
"He cherishes the memories of working with Sir Barry for an independent PNG," Ms Somare told AAP.
"Their relationship goes back 48 years and Sir Michael is grateful for Sir Barry's contributions in and out of political life."
Ms Somare said her father would issue a formal statement after he had spoken to Sir Barry's children.
Health Minister Michael Malabag took to Facebook to express his fondness for Sir Barry.
"I have many fond memories of Sir Barry over many years in the course of my career as a public servant and unionist," he said.
"Simply a great man with a colourful background. RIP sir."