Police arrested Helio Taiyang Richardson at a resort on the tourist island on Thursday (Sept 12) after receiving an Interpol red notice for him, reports the Bangkok Post.
Mr Richardson is accused of multiple sexual assaults and rapes in a total of 15 cases in Australia dating back to 2017.
Police said he entered Thailand on June 16 with a tourist visa that he renewed for another 30 days, which expired on Aug 15. He had also applied for a retirement visa but that decision was put on hold after Immigration police received the red notice from Interpol.
Mr Richardson will be deported to Australia for prosecution, police said.