Australia Day Council chairman Adam Gilchrist says Australians are in danger of becoming obsessed with the "silly behaviour" of celebrities instead of admiring people of "substance".

The former cricketer made his remarks at a celebration at a Parliament House gathering to mark the 50th anniversary of the Australian of the Year awards.

This year's Australian of the Year will be announced later today, and last night dozens of past winners including author Tom Keneally and philanthropist Dick Smith gathered to mark the occasion.

Gilchrist said the awards gave the public the chance to admire the achievements of Australians from all walks of life.

"As our obsession with celebrity continues to grow, renown seems to come these days, for at least a few, from a few minutes of silly behaviour or even a funny clip on YouTube, and in that is perhaps not too much to admire," he said.

"The Australian of the Year awards give us and, more importantly, our children, genuine role models of substance.

"Some of them already are big names and have high profiles, others are not so well known outside their field.

"In either case they are acknowledged not for how well we might know their names but for their sustained and enduring effort over many years to make Australia a much better place."

This year's winner will come from a field of finalists who are relatively unknown to most, such as human rights advocate Professor Patricia Easteal and tasmanian devil expert Bruce Englefield.

Environmentalist Jon Dee, filmmaker Warwick Thornton, Indigenous educator Chris Sarra, Alzheimer's expert Professor Ralph Martins and charity founder and Bali bombing victim Julian Burton are also up for the award.

Prime Minister Kevin Rudd will announce the winner, who will take over from 2009 Australian of the Year Professor Mick Dodson, at a celebration this evening in Canberra.

Past Australians of the Year include Cathy Freeman, Paul Hogan, The Seekers and Manning Clark.