Filming on the Ridley Scott blockbuster was halted in March due to the coronavirus pandemic, but the production resumed on Monday.
Comer is pictured in a pink and yellow Middle Ages-style costume with her hair plaited around her head.
The Liverpudlian actress, 27, is seen wearing a face visor in the images.
Comer’s co-stars Damon and Adam Driver were also pictured wearing PPE on set.
The Last Duel is filming at Ardmore Studios in County Wicklow, south of Dublin, Ireland.
Damon, 49 found himself in lockdown in the area after filming was put on hold, with the actor becoming somewhat of a sensation among locals as he was spotted around the town.
Damon stayed in Dalkey, a seaside suburb of Dublin, accompanied by his wife Luciana Barroso and their four children.
Delighted locals shared snaps of the actor out and about in the town on social media.
In an interview with local radio station Spin 1038, Damon described his life in Dublin as a “fairy tale”.
“Even in the lockdown, they’re like, ‘you got to stay within two kilometres of your house’. Two kilometres here, there’s trees and forests and woods and ocean and I can’t think of any place you’d rather want to be in a two-kilometre radius of,” he said.
“It feels a bit, you know, like a fairy tale here.”
The Last Duel is based on the 2004 book The Last Duel: A True Story of Trial by Combat in Medieval France by Eric Jager.
The film, written by Scott, Ben Affleck and Nicole Holofcener, follows best friends Jean de Carrouges and Jacques Le Gris, who are ordered to fight to the death after Carrouges accuses Le Gris of raping his wife.
Affleck and Comer’s Killing Eve co-star Harriet Walter also star.