Opening the caption of the snaps with a string of hearts and Union Jack flags, Oh wrote, "Proud to represent 🇨🇦 w/ my fellow Order of Canada & Valour recipients @gregorycharlesofficiel @marktewks @palmerlp26 at Her Majesty Queen Elizabeth II funeral at Westminster Abbey today."
The carousel began with a shot of Oh posing on a staircase, her red and white Order of Canada medal symbolizing her Officer status significantly pinned to her black dress.
The image was followed by pictures of the Killing Eve actress with other members of the Canadian delegation, including Cross of Valour recipient Leslie Arthur Palmer, Olympic swimmer Mark Tewksbury, and musician Gregory Charles. Oh also posted a selfie outside of the Palace of Westminster, her back to the River Thames, and wrapped the snaps with a picture of her processing into Westminster Abbey beside Charles and Tewksbury earlier in the day on behalf of the Canadian delegation.
The procession also included Canadian Prime Minister Justin Trudeau and his wife, Sophie Grégoire Trudeau in addition to other national officials, the government said in a statement.
In June, the Grey's Anatomy star was appointed to the Order of Canada as an Officer, the second-highest civilian honor in Canada, BBC News reported.
Oh earned the title because of her "artistic career filled with memorable stage, television and film roles in Canada and abroad," the Canadian government said in another release.
Speaking with PEOPLE after the funeral, Tewksbury, 54, opened up about the service inside Westminster.
"I was part of the Order of Canada with Sandra Oh, the actress, and Gregory Charles, the musician. The three of us were representing Canadians," he says. "We've just been pinching ourselves the whole time! Even movie stars and TV stars get a little overwhelmed in all of this stuff."
Tewksbury, who won gold in the 100m men's backstroke event at the 1992 Summer Olympics, had a bird's eye view of the procession into the church, telling PEOPLE that Prince George, 9, and Princess Charlotte, 7, were "incredibly well-behaved" throughout.
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Karwai Tang/WireImage Prince George and Princess Charlotte
"They looked like really incredibly well-behaved kids but a little like kids, a little like, 'Wow this is a lot,' " Tewksbury says. "For little Prince George, this will be him one day, and he doesn't really know that yet. And then I thought, 'Ah, he's just lost his great-grandmother.' "
The Queen will be buried beside Prince Philip — her beloved husband of 73 years, who died in April 2021 at age 99 — and near her sister, Princess Margaret, and parents, King George VI and the Queen Mother.