American websites reported that the actor has started dating the British singer after a fan spotted them seemingly enjoying a date.
While we're yet to see any photos of the pair together, we've just been given some pretty hard-hitting evidence that the rumours are true.
Jessie was at the opening evening of the Magic Mike tour in London and shared a photo on her Instagram stories, tagging Channing.
She wrote: "Magic Mike London Opening night. Congratulations @channingtatum what a show... Ladies and Gentlemen you don't want to miss this."
It comes after Channing was spotted taking his daughter, Everly, 5, to a Jessie J concert in the States, as per the pictures.
And it seems that Channing's ex, Jenna Dewan, who is reportedly dating a Broadway actor, is totally cool with it.
A source told E!, "Jenna knew that Channing was dating and it wasn't a surprise. A friend had told her what was going on."
The source also added that as long as the couple's daughter, Everly, is Channing's priority then things should be fine.
"They are both trying their very best to give each other the space they both need to move forward in life. They want their relationship to stay healthy for their daughter Everly. They both plan to make her their very first priority," the source added.
GLAMOUR has ed a spokesperson for Jenna Dewan and is awaiting comment.
The rumours about Jessie J and Channing dating started swirling after a Twitter user, @maurerpower172, spotted them playing mini golf in Seattle.
They shared: “Who knew a mini golf job could be so crazy? Tonight I had to watch one of my asshole ex professors make out with his fiancé, then my coworker cut his hand open and had to go to the hospital, and finally Jessie j and Channing Tatum came in to play a round."[ id="1048468525327634432"]
Probably could have started with the celebrity gossip...
After being asked for more info, the Twitter user followed up that they were with a bodyguard.
They added: "They were hella nice. Jessie came down and I was shook and then when I went to get them to play, Channing turned around and I was like 👀. We hugged and got a pic and then I got to hear Jessie singing somebody to love with the radio at the end of the course."
The 38-year-old and Jessie, 30, are thought to have been seeing each other for a few months.
Eagle-eyed Jessie J fans noticed Channing at two of her recent concerts in Seattle and Salt Lake City.
A source confirmed the news to today, saying “It’s very new."
Channing and Jenna decided to separate in April.
In their joint statement, which was super positive, they wrote that there were no hard feelings and they had just decided to move on.
Channing Tatum and Jenna Dewan's daughter makes her first public appearance
“We have lovingly chosen to separate as a couple,” the statement read. “We fell deeply in love so many years ago and have had a magical journey together. Absolutely nothing has changed about how much we love one another, but love is a beautiful adventure that is taking us on different paths for now.”
Jenna also explained that there's "a lot of love" in her "new normal" and they're "very positive".
She defended Channing, when rumours began to spread that he'd been "drinking" and "flirting".
Her rep told MailOnline: "Happy to clarify that absolutely none of these rumours are true. The reason our statement was so positive [was] because that’s the reality of the situation."
GLAMOUR UK has ed a spokesperson for Jessie and Channing and is awaiting comment.