The first-ever meeting with the Kumuls will be the only pre-tournament match for Steve McCormack's men this year and will take place 10 days before they open their World Cup campaign against Tonga at Workington.
"We're delighted to secure the game against PNG," said McCormack. "We've been working on it for weeks and all the pieces have fallen into place thanks to the tremendous efforts of the two countries' boards and Featherstone Rovers, who have been fantastic in making this happen.
"It should be a tremendous game and the perfect preparation for us ahead of the Tonga game."
Papua New Guinea play their opening Group B game against France at Hull KR's Craven Park eight days later, on Sunday, October 27.
"PNG are excited by the prospect of playing their league brothers from the far north," said Kumuls general manager Matthew Matusch.
"We are really looking forward to this opportunity as this is the first time, to our knowledge, that Papua New Guinea and Scotland have played each other.
"We are aware that we will be in for a good strong clash with the Bravehearts. We're hoping for a nice warm afternoon!"
Scotland will go into camp in Workington two days before the PNG clash.