The 42-year-old singer - who was sued earlier this month for allegedly defaulting on a $500,000 bank loan - owes $901,769.65 to the State of New Jersey.
According to documents seen by gossip website TMZ.com, the No More Drama singer owes the huge sum in back taxes and it is the latest in a string of financial problems for the star.
A lawsuit filed by Bank of America in New York State Supreme Court earlier this month accused her of failing to make re-payments on a $500,000 loan she took out in 2005 since June 2012.
In another lawsuit filed last November, the singer and her husband, Martin Isaacs were also accused of defaulting on a $2.2 million loan from Manhattan's Signature Bank.
The financial institution is seeking the full loan amount, which was taken out in October 2011 and due to be paid back by July 2012, along with $58,000 in interest.
The Family Affair singer's production company, Mary Jane Productions Inc., was also named in the lawsuit.
This is the latest financial woe for Mary after her charity, The Mary J. Blige and Steve Stoute Foundation for the Advancement of Women Now Inc., was accused of mishandling funds and failing to pay back a loan last year. Speaking about the allegations, Mary previously said: "The lives of young women are at stake. I feel what they feel. I don't want them to suffer. I promised them something and I'm gonna deliver. Period.
"The problem is that I didn't have the right people in the right places doing the right things. This should have never been allowed to happen, but it did and now we are fixing it."