Oxygen in the ocean is key to biogeochemical cycling in the marine environment and is a fundamental requirement for most marine life. The global ocean oxygen inventory has been declining and oxygen minimum zones have been expanding over the past decades of ocean warming, a trend that is predicted to continue through the end of this century. This prompts the need for interdisciplinary research on marine ocean oxygen dynamics to better contextualize current and future scenarios, combining expertise from modern and paleo-oceanography, geochemistry, sedimentology, and Earth system modeling across various temporal and spatial scales. This session encourages contributions that enhance our understanding of the nature, drivers, and timing of changes in ocean oxygen dynamics in the past, present and future globally and/or locally and across various timescales (seasonal to multimillion-year). We particularly welcome studies that 1) provide new insights into the response of marine oxygen to shifting climate states and environmental conditions, and/or links to the biogeochemical cycling of carbon and nutrients in the ocean, and 2) assess future oxygen dynamics with possible implications for marine ecosystems, marine productivity, global carbon cycling, and/or the evolution of oxygen minimum zones. We invite studies based on both observational data and numerical model simulations, and on innovation and advancement in proxy development and -application specific to the investigation of marine oxygenation.