Seventh Day Baptists affirm the 66-book Protestant canon of Scripture — the 39 books of the Old Testament and the 27 books of the New Testament — as the complete and authoritative written Word of God. Books in this canon are regarded as divinely inspired and, therefore, as the supreme standard for doctrine and practice.

The SDB does not accept the Deuterocanonical books (the Apocrypha) as part of the biblical canon, following the broader Protestant tradition. The SDB Statement of Belief emphasizes that the 66 canonical books represent the entire deposit of Scripture necessary for salvation and Christian living. While other religious writings have value for instruction and edification, only the 66 canonical books possess divine authority.

The SDB affirmation of the fixed biblical canon reflects the conviction that God's revelation is complete and closed — no new books can be added to Scripture. This conviction distinguishes the SDB from traditions (such as Seventh-day Adventism and the Latter-day Saints) that accept additional canonical or near-canonical writings beyond the 66 books of the Protestant Bible.