The ITV talent contest's new spin-off involves fan-favourite former contestants returning to compete for ultimate glory - but they're not the only contenders.
Successful acts from other global adaptations of the Got Talent format will also battle to take the crown.
Singer and actress Bonnie will be among the international participants, appearing in tonight's episode.
The 24-year-old is already known in the UK for playing Bea Nilsson in Aussie soap Neighbours.
Aside from Neighbours, Bonnie has released a string of singles down under and toured with Olly Murs.
However, her entertainment career began in 2007 when she won the first series of Australia's Got Talent, aged just 12.
Speaking ahead of her appearance on BGT, Bonnie shared: "I was on the first year of Australia's got Talent, we didn't know how big it was gonna be. I thought I was just gonna sing a little bit. I mean I won! It was really weird and awesome.
"I was just in shock. It didn't feel real. I got a big giant cheque and it was a very special time in my life."
Bonnie will be seen singing on tonight's show and added: "This moment is pretty big for me. To perform will be a highlight of my career. I'm putting in a lot of practice.
"I feel like I'm 12 again, it's scary!"
You can watch a first look at Bonnie's performance of Lauren Daigle's You Say in the video above.
Other acts on Britain's Got Talent this week are father and son dance duo and all round BGT legends Stavros Flatley, 2008 winner, dancer George Sampson and reigning BGT champion, singer Colin Thackeray.
Joining them are rollerskating duo Billy & Emily England and mini magician Issy Simpson.
Alongside Bonnie, international acts competing are mime act Tape Face from New Zealand, American comedian Preacher Lawson and Mirror Family, a mirror and light dance act who first appeared on Czecho Slovakia's Got Talent.
Britain's Got Talent: The Champions airs tonight from 8:30PM on ITV.