The Protestant unionist organisation holds a “Proud to be British” rally in the Scottish capital as both sides in the independence debate make a push for votes.
Organisers said more than 10,000 people were expected to attend the event, which was marked by flute and drum bands and uniformed marchers carrying Union flags and Orange Order banners.
Henry Dunbar, grand master of the Orange Order in Scotland, was expected to tell marchers: “The No campaign has been criticised for not showing enough passion for the Union – well look out, here comes some passion.
“We are the Orangemen and women of Scotland and we are passionate about our queen and country.
“The Union is stable, strong, tolerant and prosperous – to destroy it would be unforgiveable. Together we have created a country that is the envy of the world.
“Unity is strength, and the best way of securing our future is for Scotland to remain an active and enthusiastic member of the most successful political union in history.”
Leading members of Scottish Labour and the Scottish Liberal Democrats were also campaigning for a no vote in Scotland, while Yes Scotland said it was holding the biggest day of national campaigning so far ahead of the referendum on 18 September.
The pro-independence campaign said it would deliver 2.6 million leaflets in 48 hours, and promised to have 35,000 volunteers manning 473 street stalls across Scotland.
The weekend push for votes comes after Deutsche Bank warned that the financial and economic arguments against independence are “overwhelming” and compared a Yes vote to the mistakes which led to the Great Depression.
The Scottish Government accused him of failing to take into account Scotland’s “strong fiscal position” and said it would start life as an independent nation “from stronger economic foundations than any other nation in history”.
Deputy First Minister Nicola Sturgeon said: “The Yes campaign has been carried along by a flourishing of self-confidence among people in Scotland. This means we can say with certainty to people still making up their mind: ‘Let’s do this.’
“That momentum is still growing and will soon become unstoppable, as people reject the Downing Street-orchestrated campaign to talk Scotland down.”