Guy Sebastian will represent Australia in the 60th Eurovision song contest on May 23 in Vienna, Austria.

The announcement was made at a glamorous event at the Sydney Opera House on Thursday morning, attended by a packed media contingent.

Sebastian described it as a "dream opportunity".

"I was pumped [to find out] ... You never know what you're going to get at Eurovision. It beats the local RSL," he said.

While he is yet to chose a song, Sebastian said he wanted it to be "epic".

"Either super fun or a big ballad that showcases my voice."

Sebastian's song will be announced before March 16.

However, Sebastian said he would not be singing an up-tempo song because too many other acts would do that.

"I don't want anything to take away from my voice," he said.

"I've boiled it down to a couple of songs and they're both ballads."

The former Australian Idol winner has prior experience of global song contests, having finished seventh at the 2003 World Idol final, where he was praised by Simon Cowell as one of the best voices at the event. He has also performed for the Pope Benedict XVI, Queen Elizabeth II and Oprah Winfrey.

"I haven't been been voted on in years though. Over the last 12 years I've had a lot more experience ... I'll be drawing on that to hopefully not screw it up.

"I want to go huge with the screens," he added.

CONGRATULATIONS @guysebastian who is representing Australia in #SBSEurovision Song Contest… http://t.co/4u14VzOPuI pic.twitter.com/lq03ntnnQU — Sony Music Australia (@SonyMusicAU) March 4, 2015

It seems Sebastian is doing it for the challenge and exposure, having revealed that he would not be paid.

But if he were to win and was to go back as a winner? "I'd be getting paid then."

Paul Clarke, head of Australia's Eurovision delegation and director of Blink TV, said Sebastian was always the first choice, although artists including Sia, 5 Seconds of Summer and Iggy Azalea were in the mix, with a final shortlist of six artists.

"We talked to Sia ... her timing was bad because she wanted to do the Grammys and it didn't work for her. But we don't want to suggest someone said no so we went for Guy," he said.

"There were a number of artists that really let us know we're interested ... [but] when you weighed everything up Guy was by far the strongest.

"He's the most popular male artist there's ever been in this country. He's had six number one singles, but personally he's just got a voice that moves me... it reminds of me of Stevie Wonder and Al Green."

Mr Clarke said the next step was to agree on a song - it won't be up to Sebastian alone - and make a video clip by March 16.

SBS managing director Michael Ebeid shed light on the process that led to Sebastian's selection.

"We wanted someone with a brilliant voice and there's no doubting Guy has that. Second thing was someone who has the experience to be able to handle a stage that has got a viewership of 200 million people. Some artists don't have that experience, they choke. It's a lot of pressure, we needed someone who has great experience who could do that," he said.

"And somebody who the whole country could get behind, someone who is warm and loved."

Mr Ebeid agreed Sebastian's cultural background helped.

"Australia today is so diverse and someone like Guy who's got a mixed background, like many of us do, is a true representation of what Australia is."

Unlike most of the 27 competing nations, organisers have put Australia straight through to the final of the event, to be held in the Wiener Stadhalle, Vienna. That means Australia does not have to contest the semi-finals of the event on May 19 and 21, although we do get to vote in both.

It is the first time Australia will compete at Eurovision, which may not come as a surprise given we are, at best, 16,000km away from Europe. That said, Jessica Mauboy sang at last year's event, albeit as the non-competition interval act during the second semi-final in Copenhagen.

Australia was confirmed as a shock participant at Eurovision 2015 on February 11 but all competing nations had to announce their contestants by March 16, leaving Australia a month to find a performer.

There is more than one Australian entry in 2015 however: Stockholm-based Australian Hayley Aitken has co-written Moldova's entry, I Want Your Love, to be sung by Eduard Romanyuta.

Huge congrats to @GuySebastian. Smash #Eurovision2015 brother. No pressure. A nations hopes ride on your shoulders. — David Campbell (@DavidCampbell73) March 4, 2015

Big congrats to @GuySebastian on being chosen to represent Aus at @Eurovision. Awesome choice! — Jane Kennedy (@Jane_L_Kennedy) March 4, 2015

On @GuySebastian album #Madness only "Like a drum" and "Lightning" meet "up to 3 min" rule. #eurovision #Australia Is there our song answer? — Eurovision Croatia (@EscCro) March 4, 2015