Lucy Spraggan jas split from her wife of three years, Georgina Gordon.
The X Factor star - who competed in the 2012 series - was with Georgina for a total of six years.
Lucy, 28, took to Instagram to share the sad news.
She said in an emotional post: "It's with sadness to let you know that after six years of joy, fun and true love Georgina and I have decided to part ways on our adventure.
"We have shared the most amazing times and life together, and we are truly grateful for knowing love at its full capacity.
"We will continue on our paths as the ultimate friends, and dog mums, united by the bond and memories we will always share.
"We are eternally thankful for the support you have offered to us; in this time of hardship we will appreciate space and time to deal with change."
The sad news comes six months after the couple had announced that they were having fertility treatment in order to try for a baby.
In the meantime, the singer had said they were getting plenty of practice at being parents as they had opened up their home to children in need.
We have shared the most amazing times and life together, and we are truly grateful for knowing love at its full capacity.
The couple had become foster parents, taking in 12 children so far - ranging in ages from newborns to teenagers.
Lucy told The Mirror that she and Georgina decided to act after seeing the plight of homeless Syrian refugee children on the news.
"The next day we headed to our local fostering centre in Stockport to see if we could help," she said.
Back in August, Lucy stunned fans by revealing a dramatic weight loss.
She appeared on an episode of Lorraine to plug her new album Today Was A Good Day... and also took the opportunity to explain how she did it.
Lucy told stand-in host Christine Lampard that she had made changes in her lifestyle to achieve the weight loss.
"The beer, biscuits and bread, I did that quite a while ago and I'm quite good at doing things to an excess," she admitted."I'm not drinking at all at the moment, so that makes a big difference," she continued.
"With regards to weight loss, beer, bread and biscuits... for me I had to knock them on the head."
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