Credit: Frederick M. Brown/Getty Images; Gary Miller/FilmMagic

A new Big Love!

Amanda Seyfried, 26, has been seeing Josh Hartnett, 33, since January, sources tell the new Us Weekly, on stands this week.

"Josh likes to keep things low-key, so they've just been hanging out," says a pal of the pair, who were set up by a friend.

After having hot-and-heavy romances with Ryan Phillippe and Dominic Cooper in the past, Seyfried dated an NYC real estate exec, Andrew Joblon in late 2011.

Hartnett's exes include Scarlett Johansson, Penelope Cruz and Rihanna.

For more juicy details inside Seyfried and Hartnett's new romance, pick up the new issue of Us Weekly, on stands Friday!