Having just joined the photo sharing site earlier this month, Theroux showed his admiration for Aniston Wednesday posting a photo of the actress from the 2013 Academy Awards with the hashtag, #WCW, for Woman Crush Wednesday.
The black and white photo features Aniston walking ahead with only her dazzling, fire-red Valentino gown showing any color.
Theroux captioned the artsy shot simply writing, "#wcw #valentinored #xo."
The post comes days after the screenwriter defended a character from his latest penned film, the comedy sequel Zoolander 2.
After the first trailer for the film was released in November, some fans started an online petition to boycott the film after they were offended by Cumberbatch's comedic character All, who some saw as transphobic.
Responding to the controversy, Theroux sat down with The Wrap and stated, "I don't even know what to make of it, because it hurts my feelings in a way. I take great care in the jokes I write, and the umbrage being taken is out of the context of the scene. I wish people would see the movie first. Satire is a thing that points out the idiots, and we went through it on Tropic Thunder with the 'R' word," he said referencing a similar controversy from 2008 regarding Robert Downey Jr.'s use of the word "retard."