Pandeism, or pan-deism, is a theological doctrine that combines aspects of pantheism with aspects of deism. Unlike classical deism, which holds that the creator deity does not interfere with the universe after its creation, pandeism holds that such an entity became the universe and ceased to exist as a separate entity. Pandeism purports to explain why God would create a universe and then appear to abandon it, and pandeism seeks to explain the origin and purpose of the universe.

Pantheism is the philosophical religious belief that reality, the universe, and nature are identical to divinity or a supreme entity. The physical universe is thus understood as an immanent deity, still expanding and creating, which has existed since the beginning of time. The term pantheist designates one who holds both that everything constitutes a unity and that this unity is divine, consisting of an all-encompassing, manifested god or goddess. All astronomical objects are thence viewed as parts of a sole deity.