We discuss several forms of developmental plasticity exhibited by marine crabs, in the context of ecological developmental biology (EcoDevo), and seek to motivate research in EcoDevo by addressing some key questions of the field. We summarise the diversity of plastic developmental responses exhibited during crab development, identify gaps in knowledge and highlight the importance of EcoDevo research in the light of current climate change. Marine crabs show a suite of plastic responses including transgenerational plasticity (e.g., maternal effects), as well as developmental plasticity both within the larval phase and across the larval-juvenile life history transition (e.g., latent effects). Given the potential ecological and evolutionary consequences we think that there is much potential for research in the field of EcoDevo using brachyuran crabs as model organisms.