The former Wollongong Hawks captain said he was very much looking forward to his role.

"What an honour," he said. "I was lucky enough to be captain for the Hawks and I am very honoured to be chosen for this important event. I will cherish it."

As ambassador, Mr Campbell will deliver an address at the citizenship ceremony at Wollongong Town Hall when more than 50 people will become Australian citizens.

"It is an important day for them and for our city because they will help make it a better place," Campbell said.

He will also support his former Wollongong NRE Hawks teammates at their game against the New Zealand Breakers before heading to Lang Park to introduce the Australia Day Award winners and start the celebrations.

"Mat is a champion on and off the basketball court," Lord Mayor Gordon Bradbery said. "He is an inspiration and a decent guy who is from the Gong and a great representative of what it is to be Aussie."

Donny Galella will represent the fashionable history of Kiama Municipality as the Australia Day ambassador for the area.

The fashion stylist and makeover expert appears weekly on Seven Network's The Morning Show and Foxtel's LifeStyle, and has his own fashion label.

He is following in the footsteps of internationally renowned designer Orry George Kelly, who was also born and raised in Kiama.

Celebrations will begin with the Aquathon at Wollongong Harbour at 8am and finish with the firework display at 9pm.