The couple is "fully back together" after a month-long split, according to a source who spoke to E! News.
"They took a few weeks apart, but ultimately decided they really care about each other," the source said, adding that they "seem very happy to be spending time together again."
In December, news broke that Tatum, 39, and Jessie J, 31, had split about a month earlier, after a year of dating, but sources told Us Weekly that "they are still really close and still good friends.”
"This woman just poured her heart out on stage at the Royal Albert Hall. Whoever was there got to witness something special. Wow," he captioned a photo of Jessie J as she sang in front of hundreds of fans in London.
At the time, a source told Us Weekly of the pair's romance: “It’s new, casual and they’re having fun together.”
Reps for Tatum and Jessie J did not immediately respond to Fox News' request for comment.
Fox News' Andy Sahadeo contributed to this report