This study created a new type of inflatable metamorphic origami that has the advantage of being a highly simplified deployable system capable of realizing multiple sequential motion patterns with a monolithic actuation. The main body of the proposed metamorphic origami unit was designed as a soft inflatable metamorphic origami chamber with multiple sets of contiguous/collinear creases. In response to pneumatic pressure, the metamorphic motions are characterized by an initial unfolding around the first set of contiguous/collinear creases followed by another unfolding around the second set of contiguous/collinear creases. Furthermore, the effectiveness of the proposed approach was verified by constructing a radial deployable metamorphic origami for supporting the deployable planar solar array, a circumferential deployable metamorphic origami for supporting the deployable curved-surface antenna, a multi-fingered deployable metamorphic origami grasper for grasping large-sized objects, and a leaf-shaped deployable metamorphic origami grasper for capturing heavy objects. The proposed novel metamorphic origami is expected to serve as a foundation for designing lightweight, high-deploy/fold-ratio, low-energy-consumption space deployable systems.