A total of 603 seawater samples and 125 aerosol samples were analysed for their lithium concentrations. The seawater samples were collected during eight research expeditions. All seawater lithium concentrations were normalised to TEOS-10 absolute salinity of 35 g/kg. Most seawater samples were collected using Niskin bottles and filtered using 0.22 µm filters. Exceptions are samples UW1-UW26 that were collected from the underway water system of RV Kilo Moana during cruise CDisK-IV, and surface water samples from the Red Sea that were collected using a bucket lowered from the deck of a container ship. Samples from cruises SOE09, RS2015 and RS2018 were not filtered. The seawater samples were collected during the following cruises: CDisK-IV from Hawaii to Alaska in 01-30 August 2017; SN105 from Goa to Mauritius, samples collected during 7-16 December 2015; RS2015 from the Bay of Bengal to the Mediterranean Sea, samples collected during 27 December 2015 to 3 January 2016; RS2018 from the Bay of Bengal to the Mediterranean Sea, samples collected during 23-31 March 2018; SOE09 in the Indian sector of the Southern Ocean in 12 January - 21 February 2017; JR274 in the Atlantic sector of the Southern Ocean between 9 January and 12 February 2013; D357 and JC068 sailed from South Africa to South America, mostly along 40°S, cruise D357 in 18 October – 22 November 2010, and cruise JC068 in 24 December 2011 – 27 January 2011. Daily aerosol samples were collected from the Pacific Ocean during CLIVAR-CO2 Repeat Hydrography Sections P16 and P2. The P16 section follows 150°-152°W and was divided into two legs, a southern leg from 17°S to 71°S in January-February 2005, and a northern leg from 16°S to 56°N in February-March 2006. CLIVAR-CO2 section P2 from Japan to San Diego, along 30°N was visited in June-August 2004. The aerosol data from both CLIVAR-CO2 sections include aerosol lithium concentration measured following digestion in HF:HNO3:HCl mixture and corrected for sea-salt contributions (Li xs total), the P16 data also includes aerosol lithium extracted with ultrapure deionised water (≥18 MΩ) by pulling 100 mL of deionised water within ten seconds through the filter (Li xs MQ). The aerosol dataset also includes calculation of lithium deposition flux based on the local rain rate.