The actress, 32, revealed that she and Leslie, 32, enjoyed a break at the Ananda Spa in the Himalayan foothills.
Writing alongside a smiling selfie of her and her former colleague wearing sunglasses, she described her and her friend as “two gals buzzed off [their] faces on India” and joked that they had been “robbed blind by monkeys,” adding: “We hardly put up a fight.”
She also said that they had enjoyed “yoga, spice, mamma earth and figuring out that all you’re ever looking for can be found within.”
“Corny as hell but my god is it true,” she added, before posting a string of hashtags including “#breathebabyandletthemadnessmeltaway,” “#brainalteringjoy” and “#roselesliehasmyheartandsoulwrappedupinhers.”
Other photos show the pair walking along a waterfront and a group of monkeys eating from a bowl in fruit in a hotel room.
Clarke, who played Daenerys Targaryen on the hit series, also showed off her holiday reading choices, which included Richard Powers’ Pulitzer Prize-winning novel The Overstory and Jessica Andrews’ Saltwater.
Leslie married fellow Game of Thrones star Kit Harington last summer, after meeting while playing on-screen lovers Ygritte and Jon Snow.
They tied the knot in a Scottish ceremony attended by Clarke and other stars from the HBO fantasy series, including Sophie Turner, Maisie Williams and Richard Madden.
The Jon Snow actor has previously revealed that it was “really odd” to kiss Clarke while filming scenes for the show’s final season due to her close friendship with him and his wife.
“Emilia and I had been best friends over a seven-year period and by the time we had to kiss it seemed really odd,” he told the Daily Mirror.
“Emilia, Rose and I are good friends, so even though you’re actors and it’s your job, there’s an element of weirdness when the three of us are having dinner and we had a kissing scene that day.”