Ever since 5 Seconds of Summer formed back in 2011 [1], we've gotten to know — and love — the members of the Australian pop-rock band. With Luke Hemmings providing lead vocals, Michael Clifford on guitar, Calum Hood on bass, and Ashton Irwin on drums, 5SOS has had some pretty big hits [2] like "She's So Perfect," "Youngblood," and "Want You Back." In honour of their current World War Joy Tour, with The Chainsmokers for their single "Who Do You Love," we rounded up 33 of the hottest photos of 5 Seconds of Summer, ahead. Please, by all means, enjoy these pictures.