The modest war hero and Victoria Cross recipient spoke about his life to 300 people at the 2014 Legacy Business Luncheon at Wollongong's City Diggers on Friday.

The event was an opportunity for the Special Air Service (SAS) Regiment soldier to give back to Legacy, a charity he first encountered at the age of 15 when his Vietnam veteran father Greg Donaldson died suddenly of a massive heart attack.

"For me it's very important to give back - and the capacity I can do that in now is more far-reaching than if I hadn't received a VC and hadn't been a product of Legacy's work," he said.

The charity gave his family emotional and financial support and Corporal Donaldson is still in regular contact with the legatee who visited their home.

"What that does to someone's life, what it means to that family back home, what it means to those children - it's highly valuable and important."

While serving in Afghanistan in 2008, Corporal Donaldson's unit was ambushed and nine Australian soldiers were wounded.

He deliberately drew enemy fire on several occasions so his wounded comrades could be moved to safety before running 80 metres across exposed ground to carry a wounded coalition force interpreter to safety.

Corporal Donaldson, who went from troubled teen to war hero, uses his story to inspire others.

"I always felt I had a story but when I joined the military and the cross happened after that I guess it just added a couple of extra chapters to my life and made it more interesting," he said.