This essay combines a phenomenological account of life trajectories with a practice theory approach to the social contexts in which life trajectories occur to illuminate key features of the phenomena studied by life course research, including the Doing Transitions approach. The discussion construes life trajectories, not as the events and transitions that make up the progress of life in specific life domains, but as central dimensions of a life qua continually unfolding entity. It subjects three types of trajectories so construed to analysis: space-time paths, successions of actions, and past-future arcs. It then explores the contextualization of such trajectories in constellations of social practices. The essay concludes by situating life and its trajectories in the causal order of society and reflecting on the advantages of using theories of practices in this context.