This article presents new manuscript evidence of one of the most widely read devotional texts of the Middle Ages – the Prayers and meditations (Orationes sive meditationes) of St Anselm, abbot of Le Bec and archbishop of Canterbury – to argue that some of these prayers were originally written and disseminated in the voice of a woman. Composed and copied in grammatically feminine forms, these prayers were, as I show here, deliberately designed to be used and recited by women. This new and hitherto completely overlooked evidence is transformative for our understanding of women's active voices in medieval cultures of devotion.