Fully conjugated block copolymers that covalently link donor and acceptor units within the molecular structure have the potential to simultaneously control the mesoscale assembly and interfacial structure. As a consequence, utilizing block copolymers as the active layer provides a unique opportunity to tune charge and energy transfer processes while retaining a mesoscale scaffold for efficient charge extraction within photovoltaic devices. Recent progress in synthesis, structural characterization, modeling, and device fabrication suggest significant advances in block copolymer materials are in the near future both as model materials for systematic studies of charge and energy transfer and as high performance materials for photovoltaic devices. In this Perspective, we describe recent efforts, current challenges, and opportunities in the development of fully conjugated block copolymers for organic photovoltaics.