Ecologists have long treated populations as homogeneous entities, assuming that variation among individuals can be safely ignored. Yet, no population is homogeneous. Individuals vary substantially in their phenotypes, behaviors, and life-history traits above and beyond their differences in age, size and sex. Although the evolutionary importance of such intraspecific variation is widely appreciated, much less is known about when and how intraspecific variation influences ecological dynamics and community structure. Our symposium brings together a diverse range of perspectives from individuals making new and influential contributions to our understanding of intraspecific variation and its ecological consequences. With a list of speakers that includes both empirically-minded theoreticians and theory-minded empiricists, our goals are to (a) synthesize the many recent conceptual advances being made, (b) highlight the novel insights emerging from recent empirical experiments and observations, and (c) help translate newly developed mathematical theory into testable hypotheses for future empirical study. Our first set of selected speakers is making rapid progress in efforts to disentangle the genetic and environmental mechanisms underlying variation among individuals and how these mechanisms interact to affect community dynamics. They will (i) present novel insights from extensions of a classic ecological model, thereby laying a theoretical foundation for the speakers to follow, (ii) present empirically-parameterized simulations revealing how heritable trade-offs between inter- and intraspecific competitive ability alter the invasibility of native plant communities, (iii) provide an empirical perspective on the relationships between individual variation, species diversity, and ecosystem productivity in natural salt marshes, and (iv) combine theory with experiments that partition eco-evolutionary mechanisms to determine when intraspecific variation can alter community dynamics qualitatively. Our second set of speakers will (v) showcase the power of network theory to reveal the importance of incorporating individual heterogeneity in contact networks into SIR models of disease spread, (vi) offer new empirical insights into the patterns and implications of diet specialization in threatened sea otter populations, and (vii) present new theory that illustrates how variation among individual predators alters community stability. The final speaker will offer a synthesis of the varied mechanisms by which individual variation will affect predictions of ecological dynamics that he and colleagues of an ongoing NIMBioS working group have evaluated. The symposium will conclude with a 25 minute panel discussion whose primary goal is to engage the speakers and audience in a dialogue to identify the most pressing outstanding issues of the field.