Fans from Australia. New Zealand, Spain , France and the Netherlands are expected at the event in Aviemore, with the majority of guests expected to fly in from the United States.
The event draws on the huge community of fans of the TV series, which charts the life of Highland clan chief James Fraser, played by Sam Heughan, and his wife Lady Claire, played by Caitriona Balfe.
Organiser Jeni Hackett, of fans group Outlandish UK, said it was an occasion to celebrate “all things Outlander”.
The agenda for the weekend, from May 18 to 22, will include Highland Dancing lessons, a herbalism workshop from Claire McKay - in a nod to Lady Claire’s medical skills - and Gaelic classes.
Talks from Maggie Craig, author of Damn Rebel Bitches, Women of the ‘45, and author Hugh Allison, who will speak on Ghosts of Culloden, are also scheduled.
She said a growing number of ‘Outmanders’ - male fans - were attending such gatherings with Highland dress a popular choice for some attendees.
This is the third event of its kind organised by the group, which is run by volunteers.
Ms Hackett said: “It an absolutely lovely atmosphere at the gatherings and to start off with everyone has something in common already.
“We have a lot of people come on their own and you do feel a sense of family by the time it’s time to leave.
“I think the show has just managed to capture the beauty of Scotland and many of the fans are interested in their Scottish heritage.”
Ms Hackett said the Outlandish UK group first built up around a love of Diana Gabaldon’s Outlander best-selling books but that “things escalated” when Sam Heughan was cast to play James Fraser in the television adaption.
The show is made by entertainment giants Sony and American cable channel Starz and can be streamed in UK on Amazon Prime.
Ms Hackett, who is from Hampshire, stressed that the event was not a convention and that stars of the show were not due to be there.
However, she added that Outlander producer and writer Ronald D Moore and his wife Terry Dresbach, who designs the costumers for the show, dropped in to the last event.
Sam Heughan and a number of his co-stars are due to appear at an Outlander Convention at a hotel in Blackpool in August.
A similar event has been held in a hotel at Heathrow Airport.