Jennifer Aniston.
"Justin Theroux had an amazing birthday on Friday, receiving an extraordinary gift when his girlfriend Jennifer Aniston accepted his proposal of marriage," Theroux's representative told the celebrity magazine.
Aniston's publicist Steven Huvane confirmed the engagement.
Aniston (43) and Theroux (41) have been dating for more than a year and appeared in the comedy Wanderlust in February.
No wedding date was announced.
The marriage will be the second for Aniston, one of Hollywood's favorite actresses and a frequent face in romantic comedies.
Her first union with Brad Pitt ended in divorce after five years in 2005, when Pitt fell in love with actress Angelina Jolie. Aniston's love life has been followed assiduously ever since by the world's celebrity media.
Her previous boyfriends include singer John Mayer and actor Vince Vaughn.
Pitt and Jolie announced their engagement in April but have not publicly set a wedding date. – Reuters