Japanese Himawari-8 (H8) satellite was launched on October 7, 2014 and placed into a geostationary orbit at ~ 140.7°E. The Advanced Himawari Imager (AHI) onboard H8 provides full-disk (FD) observations every 10 minutes, in 16 solar reflectance and thermal infrared (IR) bands, with spatial resolution at nadir of 0.5-1 km and 2 km, respectively. The NOAA Advanced Clear-Sky Processor for Ocean (ACSPO) SST system, previously used with several polar-orbiting sensors, was adapted to process the AHI data. The AHI SST product is routinely validated against quality controlled in situ SSTs available from the NOAA in situ SST Quality monitor (iQuam). The product performance is monitored in the NOAA SST Quality Monitor (SQUAM) system. Typical validation statistics show a bias within ±0.2 K and standard deviation of 0.4-0.6 K. The ACSPO H8 SST is also compared with the NOAA heritage SST produced at OSPO from the Multifunctional Transport Satellite (MTSAT-2; renamed Himawari-7, or H7 after launch) and with another H8 SST produced by JAXA (Japan Aerospace Exploration Agency). This paper describes the ACSPO AHI SST processing and results of validation and comparisons. Work is underway to generate a reduced volume ACSPO AHI SST product L2C (collated in time; e.g., 1-hr instead of current 10-min) and/or L3C (additionally gridded in space). ACSPO AHI processing chain will be applied to the data of the Advanced Baseline Imager (ABI), which will be flown onboard the next generation US geostationary satellite, GOES-R, scheduled for launch in October 2016.