She tied the knot with David Balfour on Saturday in the historic venue. The couple, along with guests, who flew in for the event from as far as Abu Dhabi, then attended a reception in another part of the castle.
The 31-year-old news presenter got engaged to 28-year-old Mr Balfour, who is an engineer, on a beach in Leven, Fife three years ago.
Shearer, who is originally from Shotts, Lanarkshire, wore an antique gold silk gown.
She said: "It was my dream dress. I wanted something that would fit with a castle wedding.
"The castle is such an iconic landmark. We're over the moon to marry there."
She also spoke about how the couple had a last-minute trip to buy another wedding ring for her husband after the pair discovered it no longer fit him due to a football injury just days before the ceremony.
"We had to make an emergency dash to get a new one," she said, calling it the only blip on an otherwise perfect day it seems.
More than 200 guests are thought to have attended the celebrations at the historic capital venue, which frequently plays host to nuptials in several of its grand rooms, and also includes private tours of the Crown Jewels.