Zac Efron surprises fans in Melbourne as he joins star-studded crowd at the F1 Australian Grand Prix

Hollywood A-lister Zac Efron surprised fans in Melbourne on Sunday during the F1 Grand Prix of Australia.

Efron, 36, was joined by a star-studded crowd on the grid before the race at Albert Park.

In one snap, the High School Musical star was spotted chatting to Australian actor Sam Worthington, 47.

Efron kept it casual in a black long-sleeved T-shirt and opted for stylish sunglasses as he watched in the Oracle Red Bull Racing garage.

Award-winning actors Eric Bana and Rachel Griffiths also took part in the on-track action, along with Dylan Alcott, Andy Lee and Rebecca Harding, Samantha Jade, Bailey Smith and Chris and Bec Judd.

Hollywood A-lister Zac Efron surprised fans in Melbourne on Sunday during the F1 Grand Prix of Australia

Channel Ten stars Melissa Leong, The Inspired Uneloosen, Jonathan LaPaglia, Grant Denyer and new MasterChef judge Jean-Christophe Novell were among those in attendance.

American actor and comedian Jeremy Piven was also present at the Grand Prix. The 58-year-old was a guest in the Paramount Suite.

Piven is in Australia for his new live comedy show, which takes to the stage in Melbourne on April 2 and Sydney on April 4.

Efron’s surprise visit to Australia comes after he previously spent an entire year down under in 2020 to escape Covid-ravaged America.

Efron, 36, was joined by a star-studded crowd on the grid ahead of the race at Albert Park, in the snap chatting with Australian actor Sam Worthington

Efron, 36, was joined by a star-studded crowd on the grid ahead of the race at Albert Park, in the snap chatting with Australian actor Sam Worthington

Australian actor Sam Worthington, 47, (pictured) observed the action trackside

Australian actor Sam Worthington, 47, (pictured) observed the action trackside

Efron kept it casual in a black long-sleeved T-shirt and opted for stylish sunglasses as he watched in the Oracle Red Bull Racing garage

Efron kept it casual in a black long-sleeved T-shirt and opted for stylish sunglasses as he watched in the Oracle Red Bull Racing garage

Zac was mainly based in Byron Bay, where Thor actor Chris Hemsworth owns a $30 million mansion.

He also filmed the Stan Original film Gold in South Australia and shot scenes for his Netflix docuseries Down to Earth.

He found love in Australia with Byron Bay waitress Vanessa Valladares, but they split in April 2021 before he headed to North America.

It is believed they first met in June 2020, when Vanessa was waiting at the Byron Bay General Store cafe.

Award-winning actors Eric Bana were also among those in attendance

Award-winning actors Eric Bana were also among those in attendance

Dylan Alcott, (pictured) Andy Lee and Rebecca Harding, Samantha Jade, Bailey Smith and Chris and Bec Judd were also spotted at the Grand Prix

Dylan Alcott, (pictured) Andy Lee and Rebecca Harding, Samantha Jade, Bailey Smith and Chris and Bec Judd were also spotted at the Grand Prix