Functional trait-based approaches to community ecology have seen widespread adoption in recent years, in part because they promise to offer a predictive framework from which to project species and community responses to ongoing environmental changes. While trait based approaches have seen considerable success in helping to understand species turnover along abiotic gradients, the theoretical and empirical links between functional traits, local species interactions, and species coexistence at the local scale have seen much less development, despite widespread interest in the field. The goal of this symposium is to focus discussion from a diverse group of speakers on the challenge of predicting species coexistence from functional traits. This will include discussions of which kinds of traits might matter for species coexistence, how intraspecific trait variation might alter coexistence dynamics, and what the consequences of these relationships are for communities and ecosystems. Our symposium is specifically designed to foster synthesis between emerging theory in this area and empirical work using theory to guide expectations for how traits predict coexistence. Our hope is that progress will better help researchers face the challenge of predicting shifts in community structure and composition in a changing world.