Photosynthesis is the unique biological process responsible for the conversion of light energy into chemical forms that feed most life on Earth. In the past, photosynthesis has also been responsible for generating the biomass that was buried within the Earth’s crust and converted over geological time into fossil fuels. This stored fossil energy now powers most of our engines and many human activities. In addition, oxygenic photosynthesis, which emerged as a dominant process on the planet ~3 BYA, has shaped the atmospheric composition through O2 production and sequestration of CO2. There is now detailed knowledge of the main enzymatic processes of the photosynthetic apparatus, with the notable exception of Photosystem II and its ability, unique in biology, to perform the light-driven oxidation of water thereby generating both O2 and electrons ultimately used to fix CO2 into organic carbon. But, there is far less understanding of how the fundamental mechanisms of photosynthetic energy conversion are integrated into the metabolic circuitry of plants and microbes and the types of regulatory mechanisms that coordinate CO2 fixation with its utilization for cellular metabolism. At this moment in time, there is a pressing need for attaining an in depth knowledge of photosynthetic processes in order to develop strategies for improving the efficiency and productivity of natural photosynthesis, for designing innovative approaches to convert solar energy into high density fuel(s), and for elucidating the ways in which photosynthetic metabolism and ecosystem function/fitness will be impacted by anthropogenic activities. The 2015 Gordon Conference on Photosynthesis will bring together critical aspects of basic, knowledge driven, research with the use of that knowledge for efficient, sustained and controlled production of photosynthetic outputs. It will integrate a broad range of disciplines in order to embody the various issues that must be addressed if we are to understand photosynthesis at a level that will enable the development of innovative solar converting devices and shape the outputs of photosynthetic production to the needs of the human population in a sustainable way. The areas to be covered will include: The origin of biological catalysis The emergence of eukaryotic photosynthesis Light energy capture and its regulation Water oxidation and the integration of structure and function Electron/proton transfer reactions and their regulation The dynamics of the photosynthetic membrane(s) The biogenesis of the photosynthetic apparatus Lessons from the biodiversity of photosynthetic processes The integration of photosynthesis with nutrient availability Photochemical and inorganic catalysis in relation to photosynthesis Prospects for improving natural photosynthesis To ensure the fruitful exchange among the diverse group of scientists that will attend this meeting, the 2015 photosynthesis GRC will, as with the previous ones, encourage the presentation of unpublished, exciting data, provide a collegial atmosphere and promote interactions among participants with open discussions, structure interactive poster sessions that bring together the young talented scientists with those who are more ‘seasoned’, and create opportunities for informal and lively gatherings in the afternoons and evenings.