This is the first time that the occurrence of the deep-sea giant pycnogonid Ascorhynchus levissimus Loman, Siboga Expeditie Monographic 40:1–88, 1908 is reported from the Andaman Sea (northern Indian Ocean), thus extending its distribution from the Pacific Ocean to the Indian Ocean. Three specimens of Ascorhynchus levissimus (one ♂, two ♀♀) were collected from the Andaman Sea during two research cruises onboard the Fishery Oceanographic Research Vessel Sagar Sampada (FORV SS), using a bottom trawl operated at a depth of 600–650 m. Complete descriptions of the specimens are provided, including detailed descriptions of the male and female sexes.