Máire Bhuí Ní Laeire, a farmer’s wife who could neither read nor write, gained great acclaim in the oral tradition from the late eighteenth century due to her exceptional abilities at song making and the uncompromising disdain for the colonial establishment expressed therein. Her compositions are most closely associated with the period from the 1820s onward when the Rockite agrarian movement was at its strongest, and when millenarian belief was widespread among members of that agrarian secret society. Her songs represent an alternative tradition of thought that lived in the elusive moment of performance itself, fostered by a rich oral culture that existed parallel to official written accounts. In this unofficial, though highly influential, sphere of idea-making, the illiterate female song poet would engage with the most pressing political concerns of her community and society, demonstrating the sheer power of song for political engagement and thought formation. Three key elements of Ní Laeire’s work and legacy will be considered herein: oral aesthetics, oral composition, and training; representations of prophecy and parrhesia in the songs themselves; and a re-appraisal of the role of the illiterate Irish-speaking female song poet in the history of anti-colonial thought and activism.