The acclaimed drama’s executive producer Sally Woodward Gentle revealed the news during a masterclass at the Edinburgh TV Festival.
However, British fans will have to wait until later in the year as the BBC America production will broadcast in the US first.
Asked what she could reveal about season three, she replied: “Absolutely nothing.”
However, asked about when it would air, she added: “Don’t know about BBC. You never know about BBC transmission but I think it is sort of, say, spring-ish in America. That’s it.”
The series stars Sandra Oh as an MI5 agent on the hunt for Jodie Comer’s psychopathic assassin.
Appearing on the panel, Fiona Shaw, who plays the head of MI6’s Russia desk, said the show’s new writer Emerald Fennell had cut jokes from the drama’s second series because she thought they were too similar to those penned by original writer Phoebe Waller-Bridge.
She said: “In the beginning of season two there was a terribly rude joke about schools and nuns and it was in one draft and then it was gone.
“I said to Emerald: ‘You got rid of that?’ And she said: ‘Yes, it was too Phoebe.’
“She just thought: ‘I’m being Phoebe there, so I better stop that.’
“The writing was very different because, oh God, because Phoebe’s writing comes out of her marrow and Emerald has the ability to bolt on something to the end of something and it absolutely transforms it.”