The "Keeping Up with the Kardashians" star's attorney, Laura Wasser, has filed legal papers to end the 2014 marriage, weeks after reports suggested the couple had formally separated.
According to TMZ, Kim is seeking joint legal and physical custody of their four children - daughters North, seven, and Chicago, three, and sons Saint, five, and Psalm, who turns two in May (21).
Sources claim the split is amicable, and the pair is committed to co-parenting together.
Kim and Kanye are reportedly prepared to stick to their prenuptial agreement, and are already working on a property settlement.
The date of separation has been listed as "to be determined" on the court documents, but the couple's marriage is said to have been on the rocks for some time, particularly after a tough 2020, during which the rapper ran for U.S. President while publicly revealing they had considered aborting their first child, North.
During the same rant, which Kim claimed was a bipolar episode, Kanye also lashed out at his wife and her mother Kris Jenner for trying to keep him from his kids. He also announced he had been trying to divorce Kim for years although he later apologised for his outburst.
Representatives for the stars have yet to comment on the news.
It's Kim's third failed marriage - she was briefly wed to basketball player Kris Humphries and songwriter Damon Thomas.