Miscibility in the binary blend comprising of semicrystalline poly(ethylene oxide) (PEO) and fully amorphous poly(phenyl methacrylate) (PPhMA) was discovered for the first time. Differential scanning calorimetry, optical and scanning electron microscopy, and infrared spectroscopy were performed to characterize and demonstrate miscibility in the PEO/PPhMA system (in amorphous domains). The glass transition behavior suggests that the intermolecular interactions between the pairs are not particularly strong. The Fourier-transform infrared spectroscopy results also revealed a weak-to-moderate interaction via the phenyl ring might be likely. The overall behavior of the blend is a miscible system with weak non-specific interactions, and the apparent asymmetry in the T-g-composition relationship has been analyzed with a detailed view of partially segregated PEO crystalline domains.