Dawn ceremonies have been held in Brisbane and a wreath-laying ceremony is being held in Melbourne's Federation Square followed by a walk to Parliament house and a smoking ceremony.
In Canberra, a Sorry Day procession with people wearing the colours of the Aboriginal flag- red, black and yellow will start at the Aboriginal Tent Embassy and end at Reconciliation Place.
Labor's spokesman for reconciliation, Peter Garrett, will join stolen generation speakers and Koori performers at Sydney's First Fleet Park, near Circular Quay.
Services will be held in the Darwin botanical gardens and Victoria Square in Adelaide, while Wellington Square in East Perth will host the main West Australian event.
Sorry Day coordinator Denise Lovett Dickson says the day offers a chance to reflect upon the removal of generations of half-caste Aboriginal children from their parents and then their placement in church and state-run missions.