The Scottish-born singer underwent the operation in December after a bacterial infection spread to his heart.
In a nod to his health issues, Barnes took the stage on Sunday evening to the strains of the song Resurrection Shuffle, a track he performed on Easter Saturday in 2013 when he opened for Bruce Springsteen at Hanging Rock in Victoria.
"It's good to be here," he said after starting his set with his mega-hit Working Class Man.
"It's good to be f***ing anywhere."
Fans have at the 35th Bluesfest have been assured the event will continue next year. (Jason O'BRIEN/AAP PHOTOS)
The 67-year-old announced in February that he would be performing at the annual festival, marking his first performance since November.
Barnes was joined at Bluesfest, which began on Thursday, by a roster of Australian and international artists that includes Tom Jones, Ben Harper, Elvis Costello and The Teskey Brothers.
The musical legend has been taking fans inside his rehabilitation journey after his surgery across his social media channels, even hinting this month at new music in a post to Instagram.
"Aside from working on my fitness and health, these holidays have given me time to create, I've written a couple of new songs," he said.
Here's another song from our rehearsals yesterday. I had the pleasure of writing 'Fade to Black' with Chris Bailey from The Saints for my 'Two Fires' album. It was later also included on my 'Flesh and Wood' album. Another one I'm looking forward to playing for you on the weekend,… — Jimmy Barnes (@JimmyBarnes) pic.twitter.com/dlmqD7zEigMarch 28, 2024
The Bluesfest event, which is taking place outside Byron Bay, follows the shock cancellation of the annual Splendour in the Grass festival, due to be held near the northern NSW town in July.
It is one of a series of high-profile cancellations since 2022, with many festival organisers blaming rising costs and shrinking household budgets for the sector's woes after the turbulence of the COVID-19 pandemic.
But Bluesfest director Peter Noble assured fans the event's future was not in doubt.
"There will be a 36th," he said as he blew out the candles on a birthday cake on Sunday afternoon to celebrate Bluesfest's 35th anniversary.
"We're going to be around. I love music."
Country artist Brad Cox was one of the starts at Bluesfest 2024 in Byron Bay. (Jason O'BRIEN/AAP PHOTOS)
The future of the festival has also been guaranteed given the attraction of standout acts this year like 14-year-old US-based Gold Coast guitar star Taj Farrant who has already shared stages around the world with musicians including Carlos Santana and Rob Thomas.
"We're fortunate enough to find they're already lining up to play next year," Mr Noble told AAP on Saturday.
Tickets for the 2025 event, which will be scaled back from five days to four, are already on sale.
An estimated 70,000 people attended the previous year's Bluesfest, which has been running since 1990.
The festival ends on Monday.
