A representative for Kardashian confirmed the news to TMZ on Friday, but declined to give a statement.
A source in the Los Angeles court system told Variety that the divorce paperwork had been filed.
Sources tell TMZ that Kardashian is asking for joint legal and physical custody of the couple’s four children: daughters North, 7, and Chicago, 3, and sons Saint, 5, and Psalm, 1.
West is reportedly comfortable with joint custody, and neither party is contesting a prenuptial agreement.
The two first went public with their relationship in 2012.
The filing follows months of rumours that the relationship between the two celebrities was on the rocks.
The couple’s relationship became strained last year when West, 43, who suffers from bipolar disorder, ran an unsuccessful campaign marked by erratic statements to be elected US president under his self-styled Birthday Party.
Kardashian in July released a statement urging compassion for West’s mental heath struggles, but the couple appeared to grow further apart with the 21-time Grammy winner spending most of his time at his ranch in Wyoming and Kardashian remaining in their Calabasas mansion outside Los Angeles.
After being friends for years – West even appeared in a 2010 episode of Kourtney And Kim Take New York – two of the most famous people on the planet started dating in April 2012.
Kardashian was still legally married to professional basketball player Kris Humphries, who she notoriously split from after 72 days of marriage.
In September of that year, the new couple appeared together at Paris Fashion Week and during their relationship they would be regular fixtures on the couture circuit.
Three months later and two became three. West announced on stage during a concert in New Jersey Kardashian was expecting.
In May of the following year, the couple attended the Met Gala together, with a heavily pregnant Kardashian wearing the dress that launched a million memes.
Her floral print Givenchy gown – with matching gloves – attracted widespread mockery, with the late Robin Williams comparing her to Mrs Doubtfire.
It was one of the early examples of the Kardashian-West union electrifying the internet.
North West, the couple’s first daughter, was born in June 2013. Her name was leapt on by critics.
In October, West got down on one knee for a suitably ostentatious proposal, renting out AT&T Park in San Francisco.
Ahead of their wedding, the couple posed on the cover of Vogue, with Kardashian wearing a wedding gown.
The big day arrived on May 24 2014. The Wests tied the knot with a star-studded ceremony Fort di Belvedere in Florence, Italy. Guests included the wider Kardashian-Jenner family and Chrissy Teigen and John Legend.
A year later, Kardashian announced the family was expanding – she was pregnant with her second child, a son the couple named Saint.
In October 2016, the couple’s world was rocked when Kardashian was robbed at gunpoint during Paris Fashion Week. She was bound and gagged during the raid and later admitted she thought she would be killed.
The thieves reportedly stole jewellery worth 10 million dollars (about £7.3 million). West was in the middle of a performance in New York when told about the incident and stopped midway through the concert, citing a “family emergency”.
The following month, West was taken to hospital, reportedly suffering from “temporary psychosis due to sleep deprivation and dehydration”, it was reported at the time.
He cancelled his tour to recover. It was not the last time West’s mental state made the headlines.
In January 2018, the Wests welcomed their third child – a daughter named Chicago, named after the rapper’s hometown.
In June, West released the album Ye and publicly declared he had been diagnosed with bipolar disorder. He had earlier been strongly criticised for suggesting slavery in the US had been a “choice”.
As West occasionally returned to the headlines for his often controversial statements, he and Kardashian welcomed their fourth child, a son named Psalm, in May 2019.
The baby arrived via surrogate. In July last year, West announced he was running for president and launched his White House bid with an event in North Charleston, South Carolina.
In an often rambling speech, he told a crowd he and Kardashian considered aborting their first child.
That month he posted a series of erratic tweets, claiming his wife had tried to get him locked up by doctors. He also made a series of accusations against his mother-in-law, Kris Jenner, before claiming he had previously tried to divorce Kardashian.
Kardashian later spoke about West’s battle with bipolar disorder, saying he is a “brilliant but complicated person” whose “words sometimes do not align with his intentions”.
During the latter half of 2020, reports resurfaced that the marriage was in difficulty.
Those rumours reached fever pitch in January, with multiple US outlets suggesting divorce was imminent, claiming West had been living at his ranch in Wyoming while Kardashian had been with the children in California.