"We Can't Stop" received mixed reviews from music critics, who appreciated its overall production but were scathing towards its lyrical content.
The song was written and produced by Mike Will Made It, P-Nasty, and Rock City, with additional songwriting provided by Cyrus, Doug E. Fresh, and Slick Rick.
It peaked at number two on the Billboard Hot 100, and tied her earlier track "Party in the U.S.A." (2009) as her highest-peaking single in the country at the time.
As of January 2014, it had sold over two million copies in the United States.
The song experienced varying success internationally; it reached the peak position in countries including New Zealand and the United Kingdom, and peaked moderately in several national record charts in Europe.