A Dutchman was also found dead on Samos over the weekend, following the recent death of British TV presenter Dr Michael Mosley on the island of Symi.
Another American, Albert Calibet, is among at least three others reported missing. The US State Department has been approached for comment.
The American found dead on Mathraki was a 55-year-old man, Greek public broadcaster ERT and Athens News Agency reported on Sunday.
The holidaymaker, who has not been named, is said to have last been spotted alive in a bar last week. His body was found on a deserted beach on the small island.
It has been taken to a hospital on the larger nearby island of Corfu for an autopsy.
“Take ‘go to Samos’ off bucket list.”
Done.