This research essay examines letters of Mary Stuart, Queen of Scotland, showing her as an accomplished rhetorician. Mary's letters have gone largely unexamined by scholars, despite the new interest in the writing of women in the early modern period. On her letters she used appeals to kinship, emphasis on rank, calls to shared religion and expressions of emotion in order to support specific objectives for her letters. The flexibility and variety of the rhetoric contained within the letters from across her life show Mary to be an accomplished and competent rhetorician. The epistolary exchanges examined in this thesis were essential in maintaining Mary's diplomatic networks both during her reign and after her abdication. The letters examined in this thesis come from both published collections of Mary's letters from the nineteenth century and from original transcriptions of archival material of letters than have not been previously published or examined.