"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 at number one on the Canadian charts, and number three on the Billboard Hot 100 singles chart in the US. 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.