El Niño Southern Oscillation (ENSO) is the dominant mode of variability in the tropical Pacific at interannual timescales. Given its large-scale influence and global impacts, understanding, predicting and projecting ENSO and potential changes in ENSO is of great societal relevance. ENSO events are the result of complex ocean-atmosphere feedbacks, mediated by influences from the extra-tropical Pacific as well as Atlantic and Indian Oceans which may be stochastic in nature. As a result, ENSO events are very diverse in their initiation, development, demise, and spatial patterns, posing great challenges to our ability to predict them. Climate change is also expected to alter ENSO characteristics and the associated local and remote impacts. This session invites contributions that explore all aspects of ENSO, including its dynamics, diversity, predictability and prediction, teleconnections, impacts, and future projections from observational, theoretical and modeling perspectives. Contributions that examine the role of inter-basin interactions on ENSO development and diversity are also welcome.