Demi Lovato is non-binary and is changing their pronouns from she/her to they/them, the singer has told fans.
Non-binary people don't identify as male or female, and tend not to conform to gender norms of either.
"Today is a day I'm so happy to share more of my life with you all," Demi, who's 28, wrote on Twitter.
"I am proud to let you know that I identify as non-binary & will officially be changing my pronouns to they/them moving forward."
Demi said they came to understand their gender identity after spending time doing "healing and self-reflective work" over the past year.
Using they/them as pronouns "best represents the fluidity I feel in my gender expression", the Sorry (Not Sorry) singer added.
Every day we wake up, we are given another opportunity & chance to be who we want & wish to be. I’ve spent the majority of my life growing in front of all of you… you’ve seen the good, the bad, & everything in between. pic.twitter.com/HSBcfmNruo— Demi Lovato (@ddlovato) May 19, 2021
The singer said they are still "learning and coming into myself" and doesn't consider themselves an "expert or spokesperson" on the subject.
They said they will speak to other non-binary people in a video series about gender identity.
"I'm doing this for those out there that haven't been able to share who they truly are with their loved ones," Demi added.
"Please keep living in your truths & know I am sending so much love your way."
Many fans have said they're "proud" of Demi's announcement, with some describing the singer as a "role model".
It comes after Demi announced in March that they were pansexual - which is when someone is attracted to other people, regardless of their gender.
Throughout their career, Demi has been an outspoken supporter of LGBT rights.
Demi, along with Nick Jonas, cancelled tour dates in the US cities of Raleigh and Charlotte in 2016 after an anti-LGBT bill was passed in North Carolina.
And in 2017, they wrote a letter to the LGBTQ+ community for Billboard magazine, as part of its Pride Month coverage.
"I struggle with wrapping my head around the fact that we live in a world where love and equal rights still have to be questioned or discounted," they wrote.
Earlier this year, when two contestants on the second series of Drag Race UK discussed their non-binary identities on the BBC show, viewers told Radio 1 Newsbeat how they felt to see their gender identity represented in mainstream media.
"When I tell people, they react in a way as if it's embarrassing," one non-binary 22-year-old told Newsbeat.
"I think it's because they've never known someone like that on TV or in their life."
They said they felt able to tell their mum about their gender identity because of the representation they'd seen on TV.
UK singer Sam Smith confirmed they were non-binary, and also use they/them pronouns, in 2019.