"So much love for you" Snooki wrote.
"No matter gay, straight or bi / Lesbian, transgender life / I'm on the right track, baby / I was born to survive", she sang on the video.
In September, Siwa was named one of Time's 100 most influential people of the world, in part because of her large online following.
Jojo's brother Jayen Siwa had also commented on Jojo's video, writing, "So happy for you JoJo!" At the time, many remarked that others should refrain from labelling Siwa until she chose to do so herself.
In the video, she completed the popular Wipe It Down Challenge where you wipe the mirror and transition into a different person.
"Old Town Road" star Lil Nas X, who came out as gay in 2019, was among those to express support for Siwa, tweeting: "if u spell "swag" backwards, it's "gay". coincidence??" She then followed it with several TikTok posts and social media updates.
Siwa began her career partnership with kids' network Nickelodeon in 2017.
She also blew up while collaborating with LGBT+ "Pride House" Tiktokers, dancing in a video set to a Mia Mugavero song.
The young star further solidified her value as a brand by making a merchandise empire for children, selling bows, furniture, and toys at huge retailers such as Target and Walmart.
The 17-year-old officially came out on Twitter on Friday (22 January), sharing a photo of herself wearing a t-shirt emblazoned with the words: "Best. Gay".
Whilst thousands of fans have taken to social media to congratulate Jojo following the big news, others weren't surprised at all.
Another message she reposted, from Hilton, read: "Love you @itsjojosiwa". That's something we should be proud of.
It appears as if JoJo Siwa has come out as gay.
The overwhelming amount of support she received came almost a year after she sparked dating rumors with a family friend, Elliott Brown.