This chapter examines metaphysical questions surrounding the existence and attributes of God, according to the concept of God endorsed by classical theism. There is a brief presentation of the more common proofs for God’s existence. Traditionally, these proofs are classified as ontological, cosmological, and teleological arguments. The metaphysical requirements of the premises and their logical structure are discussed. In particular, an important theoretical device exploited in the most updated versions of the ontological argument is modal logic; the principle of sufficient reason is a crucial ingredient of the contingency argument, a refined version of the cosmological argument; and probability and explanation theory are involved in the fine-tuning argument, which is a kind of teleological argument. The chapter also investigates divine attributes: omnipotence, omniscience and perfect goodness. Many conundrums and paradoxes stem from the metaphysics of divinity such as the stone paradox affecting omnipotence, the problem of evil, and the limitations of free will in relation to God’s power. At the end, there is a short overview of the metaphysical issues concerning the Trinitarian dogma.