This chapter argues for a broader conception of ‘agency’ than is often empirically utilized within life course studies. We provide an overview of the conventional ways agency is measured and employed, "and suggest conditions..." that shape its subjective experience and how agency influences a range of life course outcomes. We build on this research by suggesting ways that the empirical treatment of agency might mirror its theoretical development. We call for further research on agency across the life course that (a) investigates aspects of temporality, optimism, and expectations that are less theorized and empirically linked with agency and (b) explores agency through a cross-cultural lens.