"Who Are You When I'm Not Looking" is a song written by Earl Bud Lee and John Wayne Wiggins and recorded by American country music artist Joe Nichols for his 2007 album Real Things.Blake Shelton covered the song for his EP All About Tonight, from which it was released as a single in September 2010. His version debuted at number 51 on the Billboard Hot Country Songs chart in September 2010.

The song is a ballad in which the narrator wants to know the characteristics his lover's hiding from him (e.g. "Do you paint your toes 'cause you bite your nails?").

The Blake Shelton music video premiered on October 1, 2010 during CMT's Big New Music Weekend. It was voted GAC's No. 1 video of 2010.

Matt Bjorke of Roughstock gave the song a four-out-of-five-star rating, calling it a "list song," but the lyrics "an emotion in which anyone who has been in love will certainly relate to." Jim Malec of American Twang gave the song a thumbs-up review, calling it an "intimate rumination on the mystery of a beautiful, graceful woman." Karlie Justus of Engine 145 gave the song a thumbs-up. She thought that Blake Shelton's performance was "flatter" than Joe Nichols', but said that the lyrics were "grounded and honest." Gary Graff of Billboard also described the song positively, saying that it "mixes humor and pathos with a sweet melody and a wry attitude."

"Who Are You When I'm Not Looking" debuted at number fifty-one on the U.S. Billboard Hot Country Songs for the week of September 18, 2010. It became Shelton's eighth number one single on the country chart dated March 5, 2011. It has sold 1,098,000 copies in the United States as of June 2013.

^*sales figures based on certification alone
^{^}shipments figures based on certification alone

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