The Grand Orange Lodge of Scotland hopes to attract up to 15,000 members to Edinburgh on the Saturday before the historic vote.
Although most of those taking part will be from Scotland, the fiercely pro-Union Protestant movement also expects some Orange bands from Northern Ireland "to show support".
The pro-Union Better Together group last night distanced itself from the Order, insisting it would "never" be part of its campaign.
Robert McLean, executive officer of the Grand Orange Lodge, said the organisation was already in positive talks with City of Edinburgh Council about the September 13 gathering.
He said: "It's basically an Orange parade. It's not just a parade for anyone. You would expect the Orange organisations to come out for a No.
"We are looking for between 10,000 and 15,000 members in the parade. The majority will be from Scotland but we would expect some of our lodges from Northern Ireland and England to show support."
The Grand Orange Lodge of Scotland has its own pro-Union campaign group, British Together.
On its website, Grand Master Henry Dunbar says the Orange Order in Scotland is "fervently opposed" to the break-up of the UK.
"Ever since the first Orange lodges were constituted in Scotland in 1797, we have been committed to a United Kingdom, headed by a constitutional monarchy.
"We are primarily a Christian and charitable fraternal organisation - we rarely step in to the political arena. However, the Union ... is a matter that unites us all.
"I remain convinced that with your help, the Grand Orange Lodge of Scotland can help ensure that we remain 'British Together'."
After the debacle of the CBI registering and then de-registering as an official campaigner in the referendum, McLean said the Grand Lodge had considered whether it should become a "permitted participant", but decided against this, as it would not spend beyond the £10,000 threshold.
"It's an educational programme we are trying to run here," he said. "We feel quite clearly that we are better together. As far as we are concerned, [the Union] is not broken so it does not need fixed. We are quite happy to stay within the UK."
Despite the increasingly heated nature of the independence debate, McLean said he did not expect the Edinburgh parade to be a flashpoint for disorder.
"We never get a counter protest at an Orange parade. We accept that for this one we could. But I'm sure the police will deal with that."
The parade promises to be one of the few large gatherings before voters go to the ballot. In 2012 and 2013, supporters of independence staged marches and rallies in Edinburgh, first in Princes Street Gardens and then on Calton Hill, which attracted thousands.
However, plans for a third and final rally this year have been ditched, with organisers urging people to focus on local events instead.
Regarding the Orange order parade, a Better Together spokesman said: "This organisation isn't part of our campaign and never will be. The best way for people who believe that we are stronger and better together as part of the UK to get involved is by speaking to undecided voters, not marching in the streets."
Yes Scotland said: "We fully respect that others have a different view and support their democratic right to express it in any legitimate and peaceful way they wish."