A man in his 60s died of Covid-19 at Guernsey's Princess Elizabeth Hospital on Sunday.
It is the island's first recorded death of a Covid patient during the second wave of the coronavirus pandemic.
Deputy Peter Ferbrache, chairman of the Civil Contingencies Authority, said his "very deepest and heartfelt condolence" went to the man's family.
He said: "I hope we do not see any more lives lost to Covid-19, but the danger this virus presents is serious."
Mr Ferbrache said after living a "near-normal life for so many months" islanders may have "felt like the virus couldn't hurt us again... but it can, and now it has".
He added: "If there was any doubt of the importance of staying at home, reporting symptoms and taking every possible precaution, there should be none now.
"This is how we protect the lives of those we love and we must maintain our resolve to see it through."
During the first wave 13 islanders lost their lives to the virus, with it presumed to be the cause of a further three deaths.