Internal gravity waves (IGWs) still pose major questions in atmospheric and ocean sciences and stellar physics. Fundamental issues include IGW radiation from various sources, reflection at boundaries, propagation through and interaction with larger-scale flows, wave-induced mean flow, wave-wave interactions, wave breaking and its implications for mixing, and parameterizing these processes in models that do not explicitly resolve IGWs. The observational record, both globally and for local small-scale processes, is not yet sufficient to yield appropriate constraints. The session aims to bring together experts from all fields of geophysical fluid dynamics working on related problems. Presentations on theoretical, modeling, experimental, and observational work on all aspects of IGWs are welcome, including those on major collaborative projects that seek to accurately resolve or parameterize IGWs in numerical models. Participation from early-career researchers is encouraged.