Owing to donor-related issues, blood shortages and transfusion-related adverse reactions have become global issues of grave concern. In vitro manufactured red blood cells (RBCs) are promising substitutes for blood donation. In the United Kingdom, a clinical trial for allogeneic mini transfusion of cultured RBCs derived from primary hematopoietic stem cells has recently begun. However, current production quantities are limited and need improved before clinical use. New methods to enhance manufacturing efficiencies have been explored, including different cell sources, bioreactors, and 3-dimensional (3D) materials; however, further research is required. In this review, we discuss various cell sources for blood cell production, recent advances in bioreactor manufacturing processes, and the clinical applications of cultured blood.