Eadmer was born of Anglo-Saxon parentage, shortly before the Norman conquest of England in 1066. He became a monk in the Benedictine monastery of Christ Church, Canterbury, where he made the acquaintance of Anselm, at that time visiting England as abbot of the Abbey of Bec. The intimacy was renewed when Anselm became archbishop of Canterbury in 1093; afterward Eadmer was not only Anselm's disciple, but also his friend and director, being formally appointed to this position by Pope Urban II. In 1120 he was nominated to the bishopric of St. Andrews , but as the Scots would not recognize the authority of the see of Canterbury he was never consecrated, and soon afterwards he resigned his claim to the bishopric. His death is generally assigned to the year 1124. Eadmer must also be credited with being one of the first serious proponents of the Catholic doctrine of the Immaculate Conception of the Blessed Virgin Mary when he defended popular traditions in his De Conceptione sanctae Mariae.

Eadmer left a large number of writings, the most important of which is his Historia novorum, a work which deals mainly with the history of England between 1066 and 1122. Although concerned principally with ecclesiastical affairs, scholars agree in regarding the Historiae as one of the ablest and most valuable writings of its kind. It was first edited by John Selden in 1623 and, with Eadmer's Vita Anselmi, has been edited by Martin Rule for the Rolls Series (London, 1884). R. W. Southern re-edited Vita Anselmi in 1963 with a facing page translation, and Geoffrey Bosanquet translated the Rolls text of Historia Novorum in 1964. The standard work on Eadmer is Southern's Saint Anselm and His Biographer.

The Vita Anselmi, written circa 1124, and first printed at Antwerp in 1551, is probably the best life of the saint. Less noteworthy are Eadmer's lives of St Dunstan, St Bregwine, archbishop of Canterbury, and St Oswald, archbishop of York; these are all printed in Henry Wharton's Anglia Sacra, part ii (1691), where a list of Eadmer's writings will be found. The manuscripts of most of Eadmer's works are preserved in the library of Corpus Christi College, Cambridge.

• Historia novorum, ed. M. Rule, Eadmeri Historia novorum in Anglia. Rolls Series 81. 1884.
• Vita S. Anselmi "Life of St Anselm" (c. 1124), ed. and tr. R.W. Southern, Eadmer, The life of St Anselm, archbishop of Canterbury. 2nd edn. OMT. Oxford, 1972.
• Vita S. Oswaldi "Life of St Oswald" and Miracula S. Oswaldi, ed. and tr. Bernard J. Muir and Andrew J. Turner, Eadmer of Canterbury. Lives and Miracles of Saints Oda, Dunstan, and Oswald. OMT. Oxford, 2006. 213-98 and 290-324; ed. J. Raine, Historians of the Church of York and its Archbishops. Rolls Series 71. 3 vols: vol 2. London, 1879. 1-40 and 41-59.
• Vita Wilfridi Episcopi "Life of Bishop Wilfrid", ed. J. Raine, Historians of the Church of York and its Archbishops. Rolls Series 71. 3 vols: vol 1. London, 1879. 161-226.
• Breviloquium Vitae Wilfridi, ed. J. Raine, Historians of the Church of York and its Archbishops. Rolls Series 71. 3 vols: vol 1. London, 1879. 227-37.
• Vita S. Odonis "Life of St Oda", Archbishop of Canterbury, ed. and tr. Bernard J. Muir and Andrew J. Turner, Eadmer of Canterbury. Lives and Miracles of Saints Oda, Dunstan, and Oswald. OMT. Oxford, 2006. 1-40.
• Vita S. Dunstani "Life of St Dunstan", Archbishop of Canterbury, and Miracula S. Dunstani, ed. and tr. Bernard J. Muir and Andrew J. Turner, Eadmer of Canterbury. Lives and Miracles of Saints Oda, Dunstan, and Oswald. OMT. Oxford, 2006. 41-159 and 160-212; ed. W. Stubbs, Memorials of St Dunstan, archbishop of Canterbury. Rolls Series 63. London, 1874. 162—249, 412—25.
• "Life of St Bregowine", Archbishop of Canterbury, ed. Henry Wharton, Anglia Sacra. London, 1691. 75-87 (where the Life is wrongly attributed to Osbern).