The increasing demand for plant proteins, along with rising awareness of the nutritional and functional roles of dietary proteins, has prompted the nutrition and food industry to explore nontraditional protein sources. Hempseed protein with its excellent nutritional value and superior digestibility has drawn great interest in both scientific and industrial fields. In this review, the chemistry and nutritional quality of hempseed protein and the health benefits of bioactive peptides derived thereof are highlighted. Processing, functionality, and application of various hemp protein products, including hempseed meal, hemp protein concentrates, and hemp protein isolates, are discussed. Moreover, recent advances in technological innovation to improve hempseed protein functionality are introduced. The objective of this review is to provide an updated summary of the research on hempseed protein and to fill the knowledge gap in the exploitation of potential nutritional, health, and processing benefits of this emerging protein source.