Structural and compositional diversities of proteins generate a number of functions for fabricating novel and advanced materials. Recent progress in protein engineering endows flexible approaches and new functionalities, which makes the fabricated materials potentially applicable in a broad spectrum of fields. Such engineering strategies by applying proteins alone or together with other molecules derive numerous functional materials such as patterned nanometal materials/nanometallic compounds, well‐designed nanocomposites, etc. Advantages in materials’ tunability, property improvement (e.g., electronic and mechanical properties, etc.), functionalities, and biocompatibility have been demonstrated, thus providing alternatives to existing materials via conventional methods. This review summarizes and discusses the strategies of fabricating functional materials using proteins as the critical contributors. Benefiting from their versatility, proteins find their roles in engineering functional materials via acting as structure‐control agents, reaction agents, and battery components, which are emphasized in this review. The strategies of each group of functions are specifically detailed. Properties of protein‐engineered functional materials and their potential applications in the fields of microelectronics, energy storage and conversion, sensor devices, etc. are also reviewed.