The fourth series is set in the late 1970s and will follow Diana's relationship with the Prince of Wales, played by Josh O'Connor.
An image released by Netflix shows Corrin wearing a new version of Diana's dress, based on the original design by David and Elizabeth Emanuel, which featured a 25ft train.
The post on the show's official Twitter account said: "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."
Corrin, a relative newcomer whose previous credits include Misbehaviour and Grantchester, will portray Diana during the early part of her relationship with Charles.
She will then hand over the role to Elizabeth Debicki.
The fourth series also stars Olivia Colman as the Queen, Helena Bonham Carter as Princess Margaret, Tobias Menzies as the Duke of Edinburgh, Erin Doherty as Princess Anne and Marion Bailey as the Queen Mother.
It has previously been announced that Imelda Staunton will replace Colman as the Queen for the final two series of the show, while Jonathan Pryce will play Philip, Debicki will play Diana and Lesley Manville will play Margaret.
The fourth series of The Crown will stream on Netflix from Sunday, November 15.