"In the Summertime" is the debut single by British rock band Mungo Jerry, released in 1970. It reached number one in charts around the world, including seven weeks on the UK Singles Chart, two weeks on one of the Canadian charts, and number three on the Billboard Hot 100 singles chart in the US. It became one of the best-selling singles of all-time, eventually selling 30 million copies. Written and composed by the band's lead singer, Ray Dorset, while working in a lab for Timex, the lyrics of the song celebrate the carefree days of summer. The track was included on the second album by the band, Electronically Tested, issued in March 1971.

Mungo Jerry are a British rock band, formed by Ray Dorset in Ashford, Middlesex, in 1970. Experiencing their greatest success in the early 1970s, with a changing line-up always fronted by Dorset, the group's biggest hit was "In the Summertime". They had nine charting singles in the UK, including two number ones, five top-20 hits in South Africa, and four in the Top 100 in Canada.