Luke Robert Hemmings is an Australian singer and musician, best known for being the lead vocalist, rhythm guitarist, and a founding member of the pop rock band 5 Seconds of Summer. Since 2014, 5 Seconds of Summer have sold more than 10 million albums, sold over two million concert tickets worldwide, and the band's songs streams surpass 7 billion, making them one of the most successful Australian musical exports in history.

5 Seconds of Summer, often shortened to 5SOS, are an Australian pop rock band from Sydney, New South Wales, formed in late 2011. The group consists of lead vocalist and rhythm guitarist Luke Hemmings, lead guitarist Michael Clifford, bassist Calum Hood, and drummer Ashton Irwin. Originally beginning their career as YouTube celebrities, they rose to international fame while touring with English-Irish boy band One Direction on their Take Me Home Tour. Since 2014, 5 Seconds of Summer have sold more than 10 million albums, sold over 2 million concert tickets worldwide, and have attained more than 7 billion streams of their songs on music streaming services, making them one of the most successful Australian musical acts in history.