Direct lineage reprogramming provides the opportunity to convert autologous cells of choice into desired cell types, including pancreatic β cells. In this dissertation, I investigated the potential of using a direct lineage reprogramming approach to generate self-regulated insulin-producing β cells from non-β cell types, in particular, the ductal epithelial cell populations in the pancreatobiliary system. In chapter 1, I will begin by reviewing β cell biology (anatomy, development and function) and pathology. I will then introduce the concept of direct lineage reprogramming, discuss its potential application in cell therapy and review previous studies using this approach. In chapter 2, I will introduce the pancreatobiliary system and explain why cells within the system can serve as potential cell sources to generate β-like cells. I will then describe experimental strategies to reprogram various ductal epithelial cell populations in the pancreatobiliary system to generate insulin producing β-like cells. First, I will describe an optimized in vitro reprogramming approach to efficiently produce insulin-secreting β-like cells from the gallbladder (main body of work is published in Stem Cell Research in 2016). Next, I will present an in vivo delivery approach to reprogram pancreatic ductal cells into insulin producing cells to treat diabetic animal models (manuscript in preparation for submission). I will discuss interesting findings stemming from this study, which suggests that the donor cell type of origin influences the molecular and functional properties of reprogrammed cells. Reprogramming approaches developed in this dissertation offer alternative treatment strategies for type 1 diabetes patients and the experimental observations made through using different cell types and reprogramming factors for cell fate conversion shed light on the mechanisms of the direct lineage reprogramming process. Based on lessons learned from these reprogramming studies, in the last chapter, I will list challenges and opportunities the field faces as well as discuss future directions for efficient direct lineage reprogramming and future strategies to develop clinical applicable cell replacement therapy.