According to Gomez, the song was intended to inspire people, and fire back at the "haters", particularly those involved in cyberbullying.

"Who Says" marks a distinct departure in sound for the band, as it has an acoustic and organic feel, compared to their dance-pop and club-oriented previous singles.

The song's accompanying music video features Gomez frolicking around a city, removing makeup, and performing with the band on a beach.

Gomez performed the song on a variety occasions including at the 2011 MuchMusic Video Awards, on Dancing with the Stars, and So Random!.

'"[1] When talking about the song's message, Gomez commented that she thought of it as "sweet", going on to say, "with bullying, with cyberbullying, with all the negativity that is in high school and dealing with things, you're already trying to figure out who you are; it doesn't help when people are constantly trying to tear you down.

[1] After debuting the single on On Air with Ryan Seacrest, Gomez mentioned the criticism received on Twitter and Facebook due to being a celebrity.

[7] Described as a "jangly pop tune", having an "overarching feel-good vibe", lyrically, the song speaks of "embracing who you are and not letting your critics get you down".

"[5] According to Brian Voerding of AOL Radio Blog, "Gomez sings about staying true to herself, particularly in the face of doubt that comes from others telling her she can't live up to her dreams".

[5] Bill Lamb of About.com said Gomez "has become the most consistent Disney pop hitmaker in recent years" and that "she has not reached these achievements through gimmickry or pandering to an audience.

"[7] Lamb went on to say that "Who Says" was no exception, complimenting Gomez's "winning vocals", and the song's "bright, catchy instrumental arrangement" and the "irresistible chorus".

[17] The music video was directed by Chris Applebaum[18] and filmed in Los Angeles, California on February 12–13, 2011.

Eventually she enters a public restroom where she changes into casual clothing, throws away the black dress and removes her make-up.

[28][29] On November 22, 2011, Gomez performed the song herself with Taylor Swift for her Speak Now World Tour in Madison Square Garden, New York.