They will host the Chiefs in Suva, Fiji, on June 30, in what will be the third Super Rugby game held in the country.
The announcement completes the team's home schedule, with its other seven home games to be played in Dunedin.
Highlanders chief executive officer Roger Clark said it was a way to help grow the game in the Pacific Islands.
“We view the game in Fiji as an opportunity to broaden the appeal of Super Rugby," he said.
"We are aware of the large following Super Rugby enjoys in Fiji and we are happy to have the chance to showcase our style of game in the islands; we are grateful to the Fijian Government and Fortress Information Systems for extending the invitation.
"Fiji has produced so many great players including our own Waisake Naholo; it will be great experience for him and all the players."
Meanwhile new head coach Aaron Mauger said it was a new opportunity the team was excited for.
"We will certainly embrace this opportunity as a team; it’s a different challenge but potentially an exciting one.
"There have been some great Super Rugby games in Fiji over the last few years and against the Chiefs we will obviously have to be at our best; but we know to be successful in Super Rugby, you have to be prepared to play anyone, anywhere, at any time."
Highlanders home games 2018
v Blues, Dunedin, 23 February 2018
v Stormers, Dunedin, 9 March 2018
v Crusaders, Dunedin, 17 March 2018
v Brumbies, Dunedin, 14 April 2018
v Lions, Dunedin, 12 May 2018
v Hurricanes, Dunedin, 1 June 2018
v Chiefs, Suva, Fiji, 30 June 2018
v Rebels, Dunedin, 14 July 2018