Baptistēs (Βαπτιστής) is a title derived from baptizō (to baptize/immerse) meaning "the Baptist" or "the Baptizer." It is used exclusively as a title for John the Baptist (Matthew 3:1; 11:11–12; 14:2, 8; 16:14; 17:13; Mark 6:24–25; 8:28; Luke 7:20, 33; 9:19). No one else in Scripture receives this title.
John the Baptist holds the unique distinction of being the only individual in Scripture identified permanently by his baptismal practice. His entire ministry was defined by this act of calling Israel to repentance through immersion — preparing the way for the Messiah. Jesus declared him the greatest among those born of women (Matthew 11:11) while also stating that the least in the kingdom of heaven is greater than he — not as a diminishment but as an invitation. John stands at the hinge of history, the last and greatest OT prophet, the forerunner of the Son of God (Malachi 3:1; Mark 1:2–3).