Arbuzynka Raion (Ukrainian: Арбузинський район) was a subdivision of Mykolaiv Oblast of Ukraine. Its administrative center was the urban-type settlement of Arbuzynka. The raion was abolished on 18 July 2020 as part of the administrative reform of Ukraine, which reduced the number of raions of Mykolaiv Oblast to four. The area of Arbuzynka Raion was merged into Pervomaisk Raion. The last estimate of the raion population was 19,269 (2020 est.)