The 12 Apostles are the men who were in Jesus's closest circle of followers. See Luke 6:13. Simon (Peter), Andrew, James, John, Philip, Bartholomew, Matthew, Thomas, James (son of Alpheus), Simon (called a Zealot), Judas (son of James) and Judas Iscariot (who betrayed Jesus). Matthias was chosen after Jesus's death to replace Judas Iscariot.