"Here comes the bride!!!!" another commented.
The first image show Corrin dressed as Lady Diana Spencer in her large ruffled wedding dress from the 1981 "fairytale wedding".
The second image shows Corrin alonside her co-star Josh O'Connor who plays her on-screen husband Prince Charles, Prince of Wales.
The Crown's Twitter account has tweeted an image of Corrin in the wedding gown.
"A first glimpse of Princess Diana's wedding dress. Emmy award-winning costume designer Amy Roberts wanted to capture the same spirit and style of David & Elizabeth Emanuel's original design, without creating a replica for Emma Corrin."
Speaking to Vanity Fair last month, Peter Morgan The Crown creator spoke about Diana's character on the show and its portrayal of her bulimia.
"It just struck me that to not represent it would be to deny the former Princess of Wales some of the true complexity of her character,"
"Her own suffering made her have compassion for other people. And it was the compassion she showed for other people that was what made everyone love her.
"Everyone has vulnerabilities and frailties. And she wore hers on her sleeve—which, of course, is the opposite of royalty.
"You're representing an idea and an ideal, and you don't want there to be too much humanity in the way," Morgan said.
The shows fourth season is set to also portray Margaret Thatcher, played by Gillian Anderson, as the show covers the years 1977 to 1990 in the new episodes.
Olivia Colman will continue her role as The Queen, Tobias Menzies as Prince Philip, Duke of Edinburgh, Helena Bonham Carter as Princess Margaret, Erin Doherty as Princess Anne, Marion Bailey as Queen Elizabeth the Queen Mother, and Charles Dance as Lord Louis Mountbatten.