The "E.T." is a song by pop singer Katy Perry from her third studio album Teenage Dream. It is one of the most popular songs of the year. As of January 2012, the tune had sold over 12 million copies worldwide. At the time of its release, "E.T." was the fourth best-selling song of the year. Although it has been retired from the official music list, the tune still makes an appearance in some of the star's live shows.

Katy Perry was a fan of outer space and science fiction in general. She has often pondered the idea of meeting up with an alien or two. A gimmick of a music video was released in which she transforms into an extraterrestrial. In it, Perry floats through space singing about the wonders of the universe. Unlike the movie version, however, the music video features no Drew Barrymore or Russell Brand.

While the song's best known contemporaries, including Beyoncé and Rihanna, haven't exactly made headlines, the song has been on the chart for more than a quarter of a century. In addition to the album's top selling single, "E.T." racked up a total of four other Billboard Hot 100 hits. With over twenty weeks on the chart, it also topped the charts in Australia, New Zealand, Canada and Poland. It also earned the dubious distinction of being the longest running number one song of all-time on the Billboard Hot 100.