Functionalized colloidal particles are fascinating due to their huge range of potential and reported applications. In this focus review, the recent development of a novel “interfacial photoreaction” for the preparation of functional polymer particles is summarized. This approach allows for the direct fabrication of hollow, capsular, non-spherical polymer particles from spherical polymer particles. Furthermore, the ability of this approach to synthesize morphology controlled particles possessing sophisticated functions, such as stimuli responsiveness and molecular recognition capability, was also described in this paper.