The couple, who married two and a half years ago, announced their separation in a joint statement released on Saturday (20 February).
It read: "It is with sadness and regret that we confirm our separation.
"It is a mutual decision, we still care deeply about each other and would like it to be known it is on amicable terms and we wish each other well."
Neither has yet filed for divorce.
The Sun reports that the split follows months of trying to make their two-and-a-half year marriage work.
Just weeks ago, rapper Pro Green, 32, told his social media fans that he and former Made In Chelsea star Millie, 26, had barely spent any time together recently.
The Lip Sync Battle UK host - whose real name is Stephen Manderson - posted: ""First day spent together all year. We had seen each other like ships in the night, we weren't getting any quality time together.
"It is good sometimes to have space but it is also difficult when you miss someone for that long."
They lived together in London, after tying the knot at Somerset's Babington House in September 2013.
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