Comer, who played killer Villanelle in the hit series, was one of the notable absentees from the 2019 nominations list.
Comer's co-star Sandra Oh – who played Eve Polastri – was nominated alongside the show itself, which aired on BBC One as well as on iPlayer.
Fans expected Comer to bag a nomination for Best Performance by an Actress In A Drama Television Series.
One wrote: “How the actual f*** was Jodie Comer not nominated for Killing Eve?!”
Another ranted: “I really don’t understand how Jodie Comer isn’t nominated for every award. Nothing against Sandra Oh, but Jodie Comer deserves ALL THE AWARDS. Jmho.”
A third wrote: “When will Jodie Comer stop being snubbed?”
How has Jodie Comer not been recognised and nominated?! https://t.co/EWKkMC6PI4— Claudia (@watsonclaudia) 6 December 2018
Many fans were already considering themselves primed to lead a “campaign for justice” after Comer, 25, was left out.
But others were overjoyed to learn Oh – who is hosting the Golden Globes in January with Andy Samberg – as well as the BBC America series picking up a nod for Best Drama.
The star-studded ceremony – which also recognises the very best in film – will be held on January 6 in Beverly Hills, California.
Oh will battle The Handmaid Tale's star Elisabeth Moss, A-Lister Julia Roberts - who appeared in Homecoming - Caitriona Balfe and Keri Russell.
Elsewhere, A Star is Born dominated the nominations with five in total - including Best Song for Shallow and Best Director for Bradley Cooper. Lady Gaga also earned a Best Actress nod for her role as Ally.
See the full list of nominees here.
Killing Eve is available in full on BBC iPlayer