Nicoletta Peddis was sent the anonymous note reading, "we have won Brexit".
The letter, which was also reportedly sent to Ms Peddis' Romanian neighbours, continued: "Its time for you to go back to werever you come from. We dont need foregneirs taking our housing our jobs our gp places.
"We wont be happy until you people leave our country [sic]."
Posting an image of the letter on Twitter, which has since been shared hundreds of times by appalled members of the public, Ms Peddis wrote: "I wasn’t sure if I wanted to share it, but then I thought about how many times in the past five years I was a victim of xenophobic episodes and remarks and I didn’t share it because it was too painful to be turned into words.
"And not sharing it really impacted my mental health.
"So, that’s why I’m sharing it today, to turn the pain and the anger into words and help me deal with the ugliness of the times we live in.
"I’m also sharing to encourage anyone who’s a victim of similar episodes to report it to the police, and to share it if you feel like talking about it."
Ms Peddis said the letters had been reported to local police, who she said were taking it "very seriously" and were "investigating to find out if this is an isolated incident or if anyone else in the area has received it".
Nicoletta, who works for Nestlé, said when she received the letter she felt shocked, angry and sad. But she said the supportive response to her tweet has made a “big difference”.
“Mostly I felt sad. It’s really unpleasant and uncalled for. Nothing this bad has happened to us in York before.
“This is another level, to receive this in your own home. It is unsettling. They know where we live. But I’m hoping it’s just them venting through a letter and I don’t feel unsafe.
“We have considered moving if I’m honest. These things make me very unhappy. It’s sad, we can go back but we have lived here most of our adult lives, our careers are here and it’s not as easy as packing up and leaving.
“York is quite a welcoming place. There’s a reason we have lived here for so long. It’s a beautiful, welcoming city.
“York shouldn’t feel ashamed, these people are everywhere. Most people are nice and welcoming but there are racist, nasty people.”
Some 1,121 racially-motivated hate crimes were reported to North Yorkshire Police between the beginning of 2018 and the end of 2020, according to the most recent data disclosed under the Freedom of Information Act.
The figure has increased year on year, although it is thought that many victims of hate crime do not report the incidents to police.
A City of York Council spokesperson said they are horrified by the letter, which has reportedly been sent to several households.
"We’ve asked anyone in receipt of this letter or any other racist or hate crime to report it on 101 where support is available too," the spokesperson said.
North Yorkshire Police has been contacted for comment.