The paper presents a 42-year (1980-2021) climate data record of global sea surface temperature (SST) derived from satellite observations, with a high degree of independence from in situ measurements. The data are generated using thermal infrared and passive microwave radiances from 22 satellite platforms, including 15 Advanced Very High Resolution Radiometers (AVHRRs), 3 Along-Track Scanning Radiometers (ATSRs), 2 Sea and Land Surface Temperature Radiometers (SLSTRs), and 2 Advanced Microwave Scanning Radiometers (AMSRs). The observations are processed to yield 1.4 × 10^12 SST observations suitable for climate applications, with an observation density varying from less than 1 km^−2 yr^−1 in 1980 to over 100 km^−2 yr^−1 after 2007. The data are provided at native resolution, averaged on a global 0.05° latitude-longitude grid, and as a daily, merged, gap-free SST analysis at 0.05°. The data include satellite-based SSTs, their corresponding time-and-depth standardized estimates, standard uncertainties, and quality flags. The accuracy, spatial coverage, and length of the record have been improved relative to previous versions, and the time series is routinely extended using consistent methods. The paper also discusses the background, methods, and technical validation of the data, including comparisons with in situ measurements.The paper presents a 42-year (1980-2021) climate data record of global sea surface temperature (SST) derived from satellite observations, with a high degree of independence from in situ measurements. The data are generated using thermal infrared and passive microwave radiances from 22 satellite platforms, including 15 Advanced Very High Resolution Radiometers (AVHRRs), 3 Along-Track Scanning Radiometers (ATSRs), 2 Sea and Land Surface Temperature Radiometers (SLSTRs), and 2 Advanced Microwave Scanning Radiometers (AMSRs). The observations are processed to yield 1.4 × 10^12 SST observations suitable for climate applications, with an observation density varying from less than 1 km^−2 yr^−1 in 1980 to over 100 km^−2 yr^−1 after 2007. The data are provided at native resolution, averaged on a global 0.05° latitude-longitude grid, and as a daily, merged, gap-free SST analysis at 0.05°. The data include satellite-based SSTs, their corresponding time-and-depth standardized estimates, standard uncertainties, and quality flags. The accuracy, spatial coverage, and length of the record have been improved relative to previous versions, and the time series is routinely extended using consistent methods. The paper also discusses the background, methods, and technical validation of the data, including comparisons with in situ measurements.