5 Seconds of Summer (also known as 5SOS) are an Australian pop punk/pop rock band.

Formed in Sydney in 2011, the band consists of Luke Hemmings (lead vocals, guitar), Michael Clifford (guitar, vocals), Calum Hood (bass guitar, vocals) and Ashton Irwin (drums, vocals). The group were originally YouTube celebrities, who posted videos of themselves covering songs from various artists in 2011. From there, they started to gain a small following in 2012 after posting a series of cover versions of popular songs onto YouTube, then rose to international fame when One Direction invited them on their Take Me Home Tour.