Has Miss Hannigan found that special someone?
News that the "Annie" and "Sex Tape" star is affianced came via Us Weekly and its "multiple sources" on Friday.
Reps for Diaz, 42, and Madden, 35, did not immediately respond to Los Angeles Times requests for comment.
"Benji always tends to fall in love easily, but this time it's for real and he landed a great girl," a source told the mag. "They obviously both make each other incredibly happy and there's nothing better than that."
In the November issue of Marie Claire, Diaz said she wasn't totally opposed to the idea of marriage but indicated that it wasn't a priority.
Diaz also deflected the rumors during her feature interview for Cosmopolitan's forthcoming January issue, philosophizing on love instead.
"You have to find someone in the same place as you are. Timing is everything," she told the mag. "If you get into a relationship where you want something the guy doesn't want, it's never going to work. You're never going to get him to be in that place. No matter how old you are, finding the guy who's in the same place as you are and wants to show up is the only way a relationship works, period."
Earlier this month, she added that she's "never said never to anything," and that includes getting hitched, E! News reported.
If the latest report is to be believed, it'll be the first walk down the aisle for both Diaz and Madden.
The leggy "Charlie's Angel" alum previously dated singer Justin Timberlake, Oscar winner
The guitarist, who is a mamber of the Madden Brothers with brother Joel Madden, was previously engaged to Australian actress Sophie Monk. He also dated Richie's "The Simple Life" costar, heiress