Cliffe, 26, has been live tweeting her preparations in the run-up to the wedding, sharing pictures of her hair and bouquet on Instagram.
Fitness instructor McKray, 27, has also been updating his followers on proceedings, admitting that he is "s**tting [his] pants" after arriving at the venue.
A live feed of pictures taken by the pair and their wedding photographer is streaming on the couple's website, and visitors can also leave their own message for the bride and groom in an online guestbook.
Cliffe and McKray fell in love on screen and got engaged last December, just weeks after the show ended.
Guests at today's ceremony are expected to include Gaz, Jay and James from MTV's Geordie Shore, but it is not yet known whether any of their fellow housemates from series 12 will attend.
A statement on the wedding site reads: "Louise and Jay wanted to offer a special thank you to their superb fans who have given them such great support since their love blossomed in the public eye live on Big Brother 2011.
"They decided the best way to do this would be invite all of their fans to the the wedding via a live feed of pictures, showing them up close and personal, along with their friends and family.
"We hope you enjoy their special day!"
Watch the moment Louise declared her love for Jay on Big Brother below: