The "exceptional contribution" of prominent Northern Ireland Orangeman Drew Nelson is to be recognised in a special project later this year, the Grand Master said.
Edward Stevenson said the former grand secretary was a towering figure within the Order.
The solicitor from Co Down died in October aged 60 after a short battle with cancer.
Mr Stevenson said: "Drew's contribution to promoting our tradition, one he was proud to represent at every opportunity, was simply outstanding.
"No other Orangeman, of perhaps any generation, will ever match his motivation and desire to see the Institution he loved succeed and flourish.
"Everything Drew did was thought out - nothing ever was off the cuff. As an organisation we have appropriately applied that same logic to ensure his legacy will quite rightly endure."
He added: "I am therefore today delighted to publicly announce our intention to recognise Drew's exceptional contribution to Orangeism and the wider community."
He said the Drew Nelson Legacy Project will be a significant initiative.
"I can confirm the extent of the project will be befitting of the individual and the vision he espoused.
"This unique venture will also be the benefactor of my designated Grand Master's Appeal.
"I have no doubt our members and many supporters will rally to make sure one of our greatest advocates is never forgotten."
Mr Nelson served as grand secretary of the Grand Orange Lodge of Ireland for 12 years, first elected in December 2004.
As a high profile spokesman and advocate, he led numerous delegations in political talks with leaders on both sides of the border.
He was also involved in outreach initiatives that led to meetings with the Irish President, the head of the Catholic Church in Ireland and saw him address the Irish Senate.