Andragogy was the first adult learning model to identify adult learners' characteristics and provide a pragmatic framework for responding to them. It is still considered a foundational and significant contribution to understanding adult learners despite substantial critique over the last 50 years. Current research supports the notion that andragogy is a useful model for designing instruction in numerous fields of practice. This chapter will look at the key ideas of andragogy, their theoretical background, the main critiques of andragogy, and the possible future of this broadly recognized approach to promoting the learning of adults.