The boyband headlined more concerts than any other major artist in Britain throughout 2012 to secure the title, after performing 34 dates in total.
"We're delighted to once again be crowned the hardest-working band of the year," JLS said.
"It means a lot that so many of our fans have had a chance to see us perform live. Thanks again for the support and we look forward to doing more in 2013."
Barney Hooper, spokesman for PRS for Music, added: "JLS have once again demonstrated that they truly know how to engage with their massive fanbase, performing live to as many of them as possible."
"Gigging is as important for the biggest performers as those starting out, and it's great to see that it is thriving in the UK.
"Congratulations to all the performers and their supporting songwriters who have together created the music that so many of us enjoy."
Westlife came in second place after performing 31 gigs as part of their farewell tour, while Steps place third, and Olly Murs and Florence + the Machine came fourth and fifth respectively.
Watch the music video for JLS's 'Hottest Girl in the World' below: