The writer was given the honour by the Saltire Society to celebrate his contribution to Scottish literature and his work in inspiring new generations of writers.
He was presented with the award at a ceremony in the Mitchell Library in Glasgow last night. McIlvaney had earlier said he was proud to be receiving an award bearing the name of Andrew Fletcher, who lived from 1655 until 1716 and was known as the Patriot for his opposition to the union of parliaments.
Jim Tough, Executive Director of the Saltire, said; "William McIlvaney has been a powerful and influential voice, not in Scottish literature but across public life for many years. His work speaks of the people and communities that were all too often absent from our literature. In a year when his early books are being brought to a new audience through re-issue by Canongate Publishers we are delighted to highlight his enormous contribution."