Joe Manganiello has a new bae -- a casual one, but still ... we're told he and actress Caitlin O'Connor have been getting to know each other on the heels of his divorce from Sofia Vergara.
Sources with direct knowledge tell TMZ ... Joe and Caitlin aren't official, but they're casually dating after meeting last month at the screening party for the second season of the HBO show, "Winning Time," in which Caitlin plays a young Dyan Cannon.
Joe and Caitlin even jumped in the jacuzzi together at the bash, albeit with other folks taking a dip too -- no solo swims here.
The party went down at the home of the show's executive producer, Jim Hecht ... and his wife, reporter Courtney Friel, shared the group snap.
Joe and Caitlin were spotted leaving Gold's Gym in Venice together Wednesday, so they obviously get along well enough to get their pump on as a duo.
We're told Joe and Caitlin bonded over the fact they're both from the greater Pittsburgh area -- he's from Mt. Lebanon and she's from Uniontown, and it all kinda snowballed from there.
As you know, Joe's new fling comes after he filed for divorce from Sofia in July, saying they've been growing apart.
While he cited the standard "irreconcilable differences" in the docs, we were told a big reason for the split was because he wanted kids and she didn't.