Citizen science has become a major component of ecological research over the past decade. With the continued advancement of information technology, many ecological questions that were only once conceptual can now be answered through the use of citizen science data. To address the current and future value of citizen science and big data, the goal of our symposium is to highlight some of the largest and most successful citizen science programs and discuss the next steps and questions that are needed in ecological citizen science research. To address our goal we have invited the top citizen science programs currently operating to give a state of the science and how it couples with the big data revolution. Given that the theme of the 2020 ESA meeting is on data science, we believe that our symposium would be of direct relevance to attendees. Because citizen science now encompasses a large number of research projects presented at ESA, our symposium will be of great value to both the research and practitioner communities.