Theroux's rep recently confirmed the rumors to Us Magazine in a detailed statement, saying that he "had an amazing birthday on Friday, receiving an extraordinary gift when his girlfriend, Jennifer Aniston, accepted his proposal of marriage."
The report comes just days after rumors surfaced that claimed the 43-year-old Aniston and the 41-year-old actor-screenwriter had broken up. Tabloids reported that Aniston wasn't ready to commit, but according to a statement from Aniston's representative, the story was "once again just another fabrication to sell magazines and has no relationship to reality."
While no date has been released for when the two will finally tie the knot, Aniston and Theroux started dating a little more than a year ago after working together on the comedy "Wanderlust." The couple quickly gained much media attention after they were spotted on a romantic European vacation.
Aniston and the "Rock Of Ages" star were seen in in Capri where they spent their nights at a $3,750-a-night hotel as well as on the deck of the Liberty of Lymington, boat, which rents for $17,555 a week, according to Us Weekly.
As the story seems to give Aniston a happy ending, many tabloids labeled the actress as plagued by running stories with themes predicting when she would finally fall in love and have a child.
"It's very narrow-minded, I think. It doesn't measure the level or my happiness or success in my life and my achievements or any of that," she told "CBS This Morning" earlier this year. In the same interview, she said she was happier than she'd ever been.
This will be the first marriage for Theroux star and the second for Aniston, who married Brad Pitt in July 2000. The two separated in January 2005 and finalized their divorce in October of that year.
Aniston and Theroux's engagement comes four months after Pitt and Angelina Jolie announced their engagement.