St. Paul (Apostle Paul, Paul of Tarsus) was a Jew who converted to Christianity after the death of Jesus and became an important figure in spreading the Christian Gospel. Many of his letters are preserved in the New Testament, part of the sacred scriptures of the Christian religion.
Members of the Islamic faith hold that several of the prophets of the Old Testament and also Jesus Christ were authentic prophets of God, but that the form in which their prophecies are reported in Judaeo-Christian scriptures are in part the product of human error. Only the word of God as transcribed by Mohammed in the Koran has plenary verbal inerrancy.
St. Paul does not appear in the Koran but would be regarded in Islam as a human teacher of the Christian message, and given more respect in Islamic denominations friendly to Christianity (e.g. the Ahmadi) and less so in others.