The UK Surface Ocean-Lower Atmosphere Study (UK SOLAS) marine fieldwork data set comprises all data, marine or otherwise, collected during sea-going activities. The fieldwork included eight dedicated research cruises in the eastern North Atlantic Ocean, spanning the period 2006-2008. These cross-disciplinary missions resulted in a diverse data catalogue. This includes meteorology (3-D wind speed and direction, total irradiance, Photosynthetically Active Radiation/PAR, air temperature, atmospheric pressure, humidity, aerosol optical thickness); atmospheric composition (carbon dioxide concentration, aerosol particle counts and size spectra, chemical analyses of aerosol particle composition, cloud condensation nuclei/CCN, concentrations of pollutants such as black carbon, concentrations of free radical species such as iodine monoxide and nitrate radicals); chemical and energy-fluxes across the air-sea boundary (dust deposition rates, oxygen and nitrogen fluxes, carbon dioxide fluxes, sensible heat fluxes, latent heat fluxes, momentum fluxes); biological, chemical and physical properties and processes in the sea surface micro-layer (chlorophyll concentration, bacterial production, phytoplankton and bacterial speciation, concentrations of biogenic trace compounds such as halocarbons, nitrous oxide, dimethyl sulphide/DMS and alcohols, surfactant concentrations, halogen concentrations such as iodine, iodide and iodate); biological, chemical and photochemical properties and processes in the ocean subsurface (primary productivity, trace gas production, plankton community composition, nutrient concentration, concentrations of trace metals such as iron, aluminium, manganese, magnesium and cobalt, ligand and complex metal chemistry parameters such as heme, dust dissolution, salinity, temperature, amino acids and urea, carbonate system chemistry including alkalinity); and sea-state physics (breaking waves, wave slope, whitecaps, bubble size spectra, aerosol formation, subsurface acoustics). Additionally, time series of air-sea fluxes were measured from the Norwegian weather ship, Polarfront, between 2006 and 2009. UK SOLAS scientists also participated in the Bergen Mesocosm experiment during 2008. This simulated gas exchanges and biological, chemical and photochemical properties and processes in the sea surface micro-layer under controlled conditions. The study united atmospheric and marine scientists from institutions across the UK and international collaborators. The UK SOLAS data set was intended to advance understanding of the mutual interactions between the atmosphere and the oceans, especially the chemical exchanges that affect ocean productivity, atmospheric composition and climate. It was funded by the UK Natural Environment Research Council, as the UK's contribution to the international Surface Ocean-Lower Atmosphere Study (SOLAS). The data are held at the British Oceanographic Data Centre (BODC) and have been incorporated into the National Oceanographic Database (NODB). Data collected from non-ship based activities, for example land-based atmospheric data and data resulting from campaigns using the Facility for Airborne Atmospheric Measurements (FAAM) aircraft are held at the British Atmospheric Data Centre (BADC).