From the Treasury of Daily Prayer:

St. Titus, like Timothy with whom he is often associated, was a friend and co-worker of St. Paul. Titus was a Gentile, perhaps a native of Antioch, who accompanied Paul and Barnabas to Jerusalem when they brought assistance to the Christians in Judea during a famine (Acts 11:29-30; Galatians 2:1). It is not known if he accompanied Paul on his first or second missionary journeys, but Titus was with him on the third one, when he helped reconcile the Corinthians to Paul (2 Corinthians 7:6-7) and assisted with the collection for the Church in Jerusalem (2 Corinthians 8:3-6). It was probably on the return to Jerusalem that Paul left Titus in Crete (Titus 1:4-5). Afterward, he is found working in Dalmatia (2 Timothy 4:10). According to tradition, Titus returned to Crete, where he served as bishop until he died about AD 96.