Roy Williamson was born in 1936 in Edinburgh. His mother played the piano. At school he learned to play the recorder by ear, pretending to read music. The teacher found out and banned him from music lessons. He went to Wester Elchies School, then Aberlour House and Gordonstoun in Moray. He taught seamanship and navigation at Burghead before going to Edinburgh College of Art. It was there that he met Ronnie Browne in 1955. The partnership lasted over thirty years.
Williamson teamed up with Bill Smith and Ron Cockburn to form the "Corrie Folk Trio" in 1962. Their first performance was in the Waverley Bar in St Mary's Street, Edinburgh. After a few weeks Cockburn left. They had already accepted an engagement at the Edinburgh Festival so Williamson suggested that Ronnie Browne should be brought in to make up numbers. They also added female Irish singer Paddie Bell to become the "Corrie Folk Trio and Paddie Bell". The audience was only eight people for the debut of this line-up but by the end of the festival it was house full at every performance. A corrie is a circular dip in a highland mountain. They chose it to evoke the Scottish landscape.