"Rolling in the Deep" is a song recorded by English singer-songwriter Adele for her second studio album, 21. It is the lead single and opening track on the album. The song was written by Adele and Paul Epworth. The singer herself describes it as a "dark bluesy gospel disco tune".The biggest crossover hit in the United States since 1985, "Rolling in the Deep" gained radio airplay from many different radio formats. It was first released on 29 November 2010 as the lead single from 21 in digital download format. The lyrics describe the emotions of a scorned lover.

"Rolling in the Deep" received widespread critical acclaim with praise drawn towards the song's aggressive lyrics, robust production, and Adele's vocal performance. It represented a commercial breakthrough for Adele, propelling her to global superstardom. The song reached number one in 12 countries and the top five in many more regions. It was Adele's first number-one song in the United States, reaching the top spot on many Billboard charts, including the Billboard Hot 100 where it was number one for seven weeks. By February 2012, "Rolling in the Deep" had sold over 8.7 million copies in the United States, making it the best-selling digital song by a female artist in the US, the second-best-selling digital song in the US, and Adele's best-selling single outside her native country, topping her previous best-selling "Chasing Pavements". Worldwide, it was the fifth-best-selling digital single of 2011 with sales of 8.2 million copies. As of 2019, with sales of over 20.6 million copies worldwide, "Rolling in the Deep" is the best-selling digital single of all-time. The song spent 65 weeks on the chart, making the song at that time the fourth-most weeks spent on the chart, tying the place with Jewel with her double single "Foolish Games"/"You Were Meant for Me".

Its music video received a leading seven nominations at the 2011 MTV Video Music Awards, including for Video of the Year and won three; Best Editing, Best Cinematography, and Best Art Direction." Rolling in the Deep" was also the Billboard Year-End Hot 100 Number One Single of 2011. At the 54th Annual Grammy Awards, it won; for Record of the Year, Song of the Year, and Best Short Form Music Video. Various critics and music publications ranked it as the best song of the year on their end-of-year lists with Rolling Stone ranking it number 8 on its list of "The 100 Greatest Songs of the 21st Century".