Britney Spears has arrived in Sydney ahead of her first Australian tour, which starts in Perth on Friday.

The headline-grabbing American pop princess touched down at Sydney airport just after 6am AEDT.

"Longest flight ever but we had a great time. So excited to be here," Spears tweeted on micro-blogging site Twitter after arriving.

She avoided the small group of fans who were waiting for her at the airport, instead boarding a private jet for the flight to Perth.

Spears' worldwide Circus tour - with a cast of 44 dancers, magicians, clowns and acrobats - opened in New Orleans in March.

She will perform 15 concerts in Australia - starting in Perth on Friday, followed by Melbourne, Sydney and Brisbane before finishing in Adelaide on November 29.

- AAP