Little is known about Harry's life. He was most-likely born into a noble family perhaps from the Lothians and it is thought that he was blind from birth. He is credited with writing the patriotic epic, The Life and Heroic Actions of the Renowned Sir William Wallace, General and Governor of Scotland, around 1460. This work is the main source of information on Wallace's life, and although much quoted and an influence on both Scott and Burns, it has subsequently been shown to have significant inaccuracies. There is also some doubt that this 12-volume work could be constructed solely by the blind and modest Harry, but despite these problems the poem contains a remarkable amount of information about 12th C. Scotland. The text of the poem is contained in a manuscript, now held by the National Library of Scotland, which was written in 1488 by John Ramsay, who also recorded The Bruce by John Barbour (c.1316-95).
Between 1473 and 1492, Blind Harry is recorded as being paid for performances as a minstrel at the court of James IV in Linlithgow. He may also have written several other poetic works.