A source told the magazine that the new beau is not "well known."
Previously, a source close to Dewan said that she had tentatively stepped back into the dating world and had been on a "few dates," though she "doesn't talk about a boyfriend."
Meanwhile, Tatum has reportedly struck up a relationship with British singer Jessie J. A source told PEOPLE that the relationship is "very new," while a source told Us Weekly that the two are "keeping it casual" and "having fun."
"Channing and Jessie's relationship is very new," the source said. "They truly just hit it off. Because it's only been six months since Channing and Jenna separated, this is all very new. Channing really likes Jessie."
Tatum has even reportedly attended concerts of Jessie's. "He loves that Jessie has her own successful career and he's a big fan of her music," the insider said. "He has watched her perform and has plans to attend more of her concerts."
After the two were spotted on what seemed to be a romantic getaway in Seattle last week, a witness said they kept things "low-key."
"They were super sweet, super nice people. Jessie and Channing were sitting next to each other," a witness told ET. "[Channing] had his arm around her chair but they weren't all over each other. They were very low-key."
The new romances for Dewan and Tatum come six months after they separated following nearly nine years of marriage. They made the announcement via social media, saying they had decided to "lovingly separate."
Their "very first priority," according to ET's source, is their 5-year-old daughter Everly.
"They are both trying their very best to give each other the space they both need to move forward in life," the source explained. "They want their relationship to stay healthy for their daughter Everly. They both plan to make her their very first priority."
Neither Tatum nor Dewan have commented on their reported new relationships.
Earlier in the week, Dewan shared a photo with former WWE diva Stacy Kiebler during a girls' day out. Both women smiled for a selfie as Dewan captioned it, "Thank GOD for girlfriends."
Keibler echoed Dewan's sentiments, writing, "@jennadewan said it best: Thank God for girlfriends. Never enough time with you!!!"