They met in 2012 while shooting their hit TV show, paying on-screen lovers, Wildling Ygritte and Jon Snow.
The radiant redhead also donned a cream floral headband using the same array of flowers that made up her miniature bouquet.
The notice read: "The engagement is announced between Kit, younger son of David and Deborah Harington of Worcestershire, and Rose, middle daughter of Sebastian and Candy Leslie of Aberdeenshire".
She was accompanied by her father as she arrived at Rayne church in Kirkton of Rayne, Aberdeenshire, wearing a flowing ivory gown and veil. Guests at the wedding include Game of Thrones stars Peter Dinklage, Maisie Williams, Sophie Turner and Emilia Clarke.
Bride Rose arrived nearly an hour later with her fiercely proud father, Sebastian Leslie, in his top of the range Land Rover.
A wedding date of June 23 was previously posted at Aberdeenshire's Huntly registration office.
"I was like, 'You need to factor in a Game of Thrones wedding by the way.' They [the cast] have all got to be there so the whole thing has got to shut down, '" said Kit Harrington.
The actors, who are both 31, have been dating for several years but have kept their relationship fairly low key.
Leslie left the show in 2014, but Harington's iconic character has appeared in every episode.
"I know the anticipation is killing a lot of people, and my God the build-up is fantastic". As fans recall, Leslie portrayed Ygritte, who was the love interest of Harington's Jon Snow throughout seasons 2-4.
"The country is attractive ... the northern lights are magical ... it was there that I fell in love", he said.
Traditionally, the weddings on Game of Thrones have been bloody affairs filled with stabbings, poisonings, and betrayal. I was meant to do it the day after with the lights.