Scholarship of the anonymous Old English prose Life of St. Mary of Egypt ranges from source studies and linguistic analyses to explorations of Anglo-Saxon female sexuality and comparisons to saints' lives translated by the monk Ælfric, but all of these studies have been based on either the text extant in BL MS Cotton Julius E. vii or on W. W. Skeat's edition of the Julius manuscript, Ælfric's Lives of Saints (1881-1900). There is, however, an as yet unedited fragmentary copy of the Old English Mary of Egypt in BL MS Cotton Otho B. x, a manuscript severely damaged by fire in 1731. Digital imaging of damaged manuscripts in concert with ultraviolet fluorescence and other special lighting techniques has been shown to be effective for restoring the legibility of previously inaccessible texts. By means of such digital facsimiles I have transcribed the text of Mary of Egypt in Otho B. x, have collated this text with Skeat's edition, and have discovered that Otho B. x contains textual evidence not found in Julius E. vii. In this thesis, I present my findings and discuss the significance of this new textual evidence for the Old English Life of St. Mary of Egypt.