The entire Co Londonderry Orange fraternity come together for the first time in 14 years.
Upwards of 30,000 people are expected to attend this demonstration as city meets country, with brethren from the city joining county peers.
Eleven districts – Castledawson, Coleraine, Magherafelt, Garvagh, Kilrea, Ballyronan, Macosquin, Tamlaght O’Crilly, Moneymore, Tobermore and Limavady – will join Orangemen from five city districts, three from the city, Raphoe (Co Donegal) and Claudy. They will be led by 90 bands.
The main parade moves off at 11.30am, taking in Limavady town centre to the Orange field on the outskirts of the town.
Deputy Grand Master of Ireland, the Rev Alastair Smyth, will deliver the main address. Mr Smyth is a member of Bellarena Faith Defenders LOL 984. He will be joined by the Grand Master of England Ron Bather, and Charles Cefferty, from Scotland Grand Lodge.
A lodge from Nevada in the United States – Las Vegas Purple Star LOL 212 – will join Dungiven brethren in the parade.