"E.T." is a song by American recording artist Katy Perry from her third studio album Teenage Dream (2010). Written by Perry, Dr. Luke, Max Martin, and Ammo, and produced by the last three, it was released as the album's third promotional single on August 17, 2010. The song was later announced as the album's fourth single and released on February 16, 2011. The single version features vocals by American rapper Kanye West, who also appears in its Floria Sigismondi-directed music video released on March 31, 2011.
The single topped the Billboard Hot 100—the fourth from Teenage Dream to do so—for five non-consecutive weeks and is Perry's fifth number one on the chart. It has also peaked at number one in Canada and New Zealand as well as within the top five in Australia, Ireland and the United Kingdom and the top twenty in ten other European countries.
The solo version of the song charted at number forty-two on the Billboard Hot 100 following its release as a promotional single, selling 64,000 digital copies. It debuted the same week on the Canadian Hot 100 at number thirteen. In Australia, the song debuted at number twelve and peaked at number five for two weeks in February 2011. It has since been certified double platinum by the Australian Recording Industry Association. One week after debuting at number seventeen, "E.T." topped the New Zealand Singles Chart on January 31, 2011, becoming her sixth number-one in the country, and has been certified platinum by the Recording Industry Association of New Zealand for sales of 15,000. On February 26, 2011, the solo version of the song entered Billboard's Hot Dance Club Songs chart at number thirty-six, and has since topped it: her sixth number-one on the chart.