Fifty North Down lodges and bands will step out under the shadow of the landmark Scrabo Tower.
Joining Newtownards brethren will be Holywood, Upper Ards and Bangor districts, as well as visiting participants from England, Scotland and Wales.
Thousands of spectators will line the streets for the parade which commences at noon from John Street, proceeding through the town centre to the demonstration field at Dairy Hall playing fields.
Co Down Grand Master Victor Harrison will be joined at platform proceedings by the Grand Chaplain the Rev Ron Johnstone, and Strangford DUP MP Jim Shannon. Following the religious service and entertainment provided at the field, the return parade will leave at 4.30pm.