Lead characters Jamie and Claire Fraser (played by Sam Heughan and Caitriona Balfe) find themselves in 18th Century North Carolina this time around, with the Fraser clan setting up home after being shipwrecked travelling back to Scotland from Jamaica.
While time travelling shenanigans, romance and stunning scenery are some of the major attractions of the show, the beautiful period costumes are also a big part of the allure.
But while they look impressive, are the character's outfits actually historically accurate?
Dressing two time periods
As the Outlander series takes place in two different time periods - 1945 and 1743 - two distinct styles of dress had to be created to authentically represent each.
The 1940s dress is more tailored and elegant, with women often shown in simple, yet stylish outfits, occasionally with hats, while the men are shown in fitted suits.
Caitriona Balfe's character, Claire, is from the 1940s, just after World War II, but is mysteriously transported back to 1740s Scotland, making her a tricky character to accurately dress for the 18th century.
During this period, women would typically have worn trousers and may have been part of the first generation of women in the workforce, meaning she would have been used to practical clothing.
However, dress in 1743 was much more fussy, with women wearing heavily embroidered dresses, complete with a tight corset bodice and a panniers underneath the skirts.
Costume designer Terry Dresbach took inspiration from Christian Dior to create the look for Balfe's character, developing outfits which show her interpreting 18th century fashion to fit her tastes.
Speaking to Vanity Fair, Dresbach said, "I wanted Claire and [Christian Dior] to converge in history so that they were both stripping these clothes of all the extra bits and getting down to the essential silhouette that defines the New Look and then defines Claire as a modern women in the 18th century."
Dresbach dismissed claims Balfe's fashion is incorrect for the period, stating, "It's not [accurate], but it's not supposed to be.
"Claire is not an 18th century woman. She's a woman of the ‘40s re-interpreting 18th century fashion to fit her tastes."
The tartan debate
The costumes which have come under fire the most in the series is the tartan of the Fraser clan.
The outfits in the show are dark in colour, with the earthy grey and blue tones designed to reflect the dirty environment the characters live in.
But the somewhat drab colour palate of the Fraser clan's tartan has angered some viewers, with fans claiming the cast should be wearing outfits that are much more brightly coloured.
Although, Dresbach defends her choice of a more demure option, telling Elle, "There's certainly a school of thought that says that tartans are actually something that was invented by the Victorians as sort of a romanticism of Scotland, that the clan tartans - and all those crazy colors - really isn't accurate to the 18th century.
"What I did was I tried to put myself in the head of somebody in the 18th century.
"So if I'm a weaver or a dyer or a fabric maker and I'm living in a little smoky hovel with three generations and maybe cow and pig in the corner, and it's pouring rain outside all the time, how much time am I spending with that giant pot over the fireplace [dyeing fabric and] getting the exact correct shade of lavender? Probably not a lot."