Did St. Paul ever claim prophethood? Much of Christianity is based on St. Paul's writings.  Did Saul of Tarsus ever claim to be a prophet of God anywhere in the new testament?
Paul did not explicitly claim to be a Prophet although there were occasions where he acted as one (cf. Acts 13 &amp; Acts 27), however he did claim  to be personally called as an Apostle by the risen Christ Jesus.
The Apostles were specifically set apart by Jesus and given authority to teach and are generally considered by Christians to have either equivalent or greater authority to Prophets in regard to their writings:

Consequently, you are no longer foreigners and strangers, but fellow citizens with God’s people and also members of his household, built on the foundation of the apostles and prophets, with Christ Jesus himself as the chief cornerstone. Ephesians 2:19-20 NIV
And God has placed in the church first of all apostles, second prophets, third teachers, then miracles, then gifts of healing, of helping, of guidance, and of different kinds of tongues. - 1 Corinthians 12:28 NIV