Artist Chris Rutterford spent more than a year completing the giant work, which has gone on show ahead of the 701st anniversary of the battle.
The mural was crowd-funded, with people making donations to have their faces included as soldiers in the conflict.
Famous faces appearing alongside Robert the Bruce include Lorraine Kelly and former Scotland rugby star Al Kellock.
One of the warriors is even pictured holding his pet cat in one hand and a battle axe in the other.
Mr Rutterford, who has previously painted murals depicting Edinburgh's Hogmanay celebrations and Robert Burns' poem Tam O'Shanter, said he wanted to "emphasise the heartbeat of humanity at the historic site".
He said: "As a proud Scot the Battle of Bannockburn is something I've always wanted to paint. It's a defining moment in Scottish history and such a powerful story.
"To have it hung on the battlefield is a huge honour.
"I think you need real diversity in the crowd, and everyone is allowed to have their own perspective on it. For me, allowing people to add their character to the image is the only way to give it a ring of truth."
Robert the Bruce won a famous victory against King Edward II of England at the battle on 23 and 24 June, 1314.
The mural will be on show in the courtyard of the Bannockburn visitor centre until 31 October.
A 30-metre mural depicting the Battle of Bannockburn has gone on display at the battlefield it depicts.