Fans were surprised, as she's given interviews in the past with an English accent and she was winning the award for playing the U.K. Prime Minister Margaret Thatcher on the Netflix drama series. However, Anderson is actually bidialectal, and speaks naturally in either accent depending on the circumstances.
Speaking with ET's Lauren Zima ahead of the 2021 Critics' Choice Awards on Sunday, Anderson said she didn't know about the swarm of accent confusion until much later.
"I don't have social media on my phone so I wasn't [aware]. A couple people texted to say that something was going on," she shared. "I didn't pay any attention to it because it's just something that I live."
"I grew up between two countries and so depending on who is in my ear is which direction my accent goes," she explained. "So I'm so used to it that it's kind of old news for me."
The 52-year-old actress was born in Chicago and moved to London when she was 5. When she was 11, she moved back to the United States and lived in Michigan, spending enough time in both the U.S. and Britain to become accustomed to both accents, per The Guardian.
The question regarding her accent was thrown into the spotlight even more dramatically when Alec Baldwin posted an offhanded joke on Twitter, writing, "Switching accents? That sounds … fascinating."
For Anderson, however, it doesn't seem like the tweet -- or questions regarding her accent -- bother her enough to even register on her radar.
"It's so not a newsworthy item, but I'm sad that it's caused him so much distress," Anderson said of the backlash against Baldwin.
Meanwhile, Anderson's performance in The Crown earned her another nomination at this year's Critics' Choice Awards -- which is just one of six nominations the period drama earned across five categories.
In a normal awards season, these shows would be a time for celebration and revelry as casts reunited at the black-tie galas. However, with the coronavirus keeping everyone safely apart, the fun of the awards season has been understandably dampened a bit.
Anderson explained how, after the big wins at the Golden Globes, the cast of The Crown kept in touch via text and calls, but it wasn't quite the same as being able to celebrate in person.
"We were all texting each other when everybody won, we were all texting each other, and so that's nice," she shared. "But it is sad not to get to be in the same room and have a laugh and properly cheer each other on."
"Well, getting up there in front of that room whether, that room is the Golden Globe room or the SAG room or whatever it is, is unbelievably intimidating," she explained. "It's intense! So, you know, to be able to sit in a hotel room and sit on a sofa and be alone and not see the hundreds of people, or maybe thousands of people who may be watching, is kind of a cool gig."