On Monday, the 25-year-old, who is from the Netherlands, shared a video titled “I’m coming out”.
In it, she explains her decision was forced by someone attempting to “blackmail” and publicly out her.
Known as NikkieTutorials, she is one of the most influential names in the platform’s beauty community.
She has been sharing make-up tutorials and reviews for 11 years and has almost 13 million subscribers. Her success has seen her collaborate with celebrities including Lady Gaga, and last year she was named a global artistry adviser for Marc Jacobs beauty.
‘I’m coming out’
De Jager opens the 17-minute video by saying she had always wanted to share her story on her own terms, but having had the opportunity “taken away” wished to reclaim her own “power”.
“I can’t believe I’m saying this today to all of you for the entire world to see. But damn, it feels good to finally do it. It is time to let go and be truly free,” she says in the introduction.
“When I was younger, I was born in the wrong body, which means that I am transgender now.”
In the video, de Jager reveals she was born male but had always identified as female growing up.
She said that by age six – with her parents’ support – she began growing her hair out and by age seven or eight wore only female clothing.
She then started taking hormones and growth suppressors at age 14 and was “fully transitioned” by 19, she explains in the clip.
“Oh my god this is so liberating. You had no idea that for 11 years that I’ve had my channel, this has been with me, and I always wanted to share this with you,” she tells her fans.
“But I cannot believe that after today, the world will know. But there’s one thing that I really, really want to make so clear to all of you. I am me. I am still Nikki. Nothing changes about that.”
At one point she addresses the people she says are threatening her and makes a middle-finger gesture, telling them: “This one’s for you”
She also expresses her hope that her video may help and inspire others.
“If you feel like you’re trapped and there’s no way out, know that it gets better. Trust me, it gets better,” she says towards the end of the clip.
The video has been met with an overwhelmingly supportive response from fans, other YouTubers and members of the LGBT community.
“I think she is an incredible woman, and I am so proud of her for sharing her story,” UK-based YouTuber SophDoesLife, who has one million subscribers, told the BBC.
“She is an inspiration to so many people, and I am so happy that she can now live her truth and feel free. She definitely has all our support in the beauty community.”
Jinkx Monsoon, an American drag queen and former winner of Ru Paul’s Drag Race, was among those who congratulated the beauty guru for “reclaiming” her story.
“NO ONE has the right to out anybody else. Period. Coming out is a personal thing, and you do not get to decide that for someone else,” she wrote on Twitter. “I’m so sorry, Nikkie, that you went through that, but I applaud how you handled it.”
At one point in the video, referencing a common segment on her channel, de Jager announced that her “Dutch Word of the Day” was vrouw – meaning woman.
A number of Dutch politicians have praised the YouTube star. Ingrid van Engelshoven, the minister of education, culture and science, described her as “brave” and a “role model”.
“You’re truly free if you can be who you are. Role models are of great importance for emancipation,” she wrote (in Dutch) in a tweet.
De Jager responded to the influx of support with a series of emotional Instagram stories on Tuesday morning.
“What happened last night is something I never, ever would dare to dream about,” she said, in tears. “The incredible amount of love and support and warmth means so much to me.”