This study investigates Mark’s involvement in the writing of 1 Peter in light of the practice of first century letter writing. Many scholars argue that 1 Peter originated from within a Petrine group in Rome that included Silvanus and Mark, ignoring the possibility that Peter might have employed an amanuensis while composing his epistle, a prominent practice of first century letter writers. By contrast, a considerable number of scholars contend that 1 Peter was penned by an amanuensis, appealing to the reference in 1 Pet 5:12, Dia. Silouanou/ u`mi/n tou/ pistou/ avdelfou/( w`j logi,zomai( diV ovli,gwn e;graya, and identifying Silvanus as its amanuensis. However, the Greco-Roman epistolary evidence shows that the formula gra, fw dia, tinoj identified only the letter-carrier. This work explores Mark’s involvement in composing 1 Peter from five angles by means of a historical and comparative approach. The five criteria are the dominant practice of using an amanuensis in first-century letter writing, the noteworthy employment of an amanuensis by Paul as a contemporary of Peter, historical connections, linguistic connections, and literary connections. Chapter 2 surveys the major proposals regarding the authorship of 1 Peter. Chapter 3 examines first century letter writing and presents the findings as a practical and supportive background for this work. The role of an amanuensis in Greco-Roman antiquity was classified as a transcriber, contributor, and composer. An amanuensis’ role as a contributor was the most common in Greco-Roman antiquity. Chapter 4 explores the process of Paul’s letter writing in light of first century letter writing, with regard to Peter’s employment of an amanuensis. It is most likely that Paul and Peter allowed an amanuensis to have a free hand if he was a gifted and a trusted colleague of them. This probability is supported by the instances that Cicero, Atticus, Quintus, and Alexander the Great employed their amanuenses as contributors. Chapter 5 investigates the close relationship between Peter and Mark through their ministry based on 1 Pet 5:13 and the references to Mark in the early church, including Papias’ note reported by Eusebius, and presents these as evidence of a historical connection between two individuals. Chapter 6 explores the syntactic correlation, the distinctive features of terminology, and the significant and frequent use of w`j for a simile between 1 Peter and Mark’s Gospel and presents them as possible evidence with the implication of linguistic connections between them. Chapter 7 examines the common Old Testament quotations (allusions) in 1 Peter and the Gospel of Mark and their conflated and integrated use of the OT and presents them as possible evidence implying a literary connection between them. 1 Peter and Mark’s Gospel outstandingly emphasize the suffering of Christ and apply the imagery of the rejected stone of Ps 118 (LXX 117):22 and that of the suffering servant of Isa 53 to His suffering. This work concludes that Mark was the contributive amanuensis for 1 Peter with Peter allowing more than a free hand in the composition.