Wendy Williams' home is apparently in the crosshairs of the federal government after it slapped her with a lien over unpaid taxes ... which they say amounts to hundreds of thousands of dollars.

According to legal docs, obtained by TMZ, the former talk show host got hit with a tax lien by Uncle Sam on her pricey NYC condo -- which records show she bought for $4.5 million in 2021 -- because the feds say Wendy owes them $568,451.57.

This unpaid balance, they claim, is a result of her owing big balances for her federal taxes for the years of 2019 and 2021.

The online records show the lien was generated in January of this year, and was recorded with the New York City Department of Finance in early February.

As of now, there doesn't appear to be any evidence the lien has been dealt with yet, but it's possible Wendy already cleared this up -- we've reached out to the court-appointed guardian of her finances, but no word back yet.

Of course, this is troubling for a number of reasons -- most, notably ... the fact that Wendy's health struggles have recently come to light, including the fact her team says she's been diagnosed with aphasia and dementia.

BTW ... Sabrina Morrissey, the guardian of Wendy's finances, was reportedly appointed sometime in Spring 2022, so she came aboard after the alleged tax violations.

The question ... is the guardian dealing with this now?