He also offered advice to the public as the coronavirus pandemic intensifies.

“I beg everyone to be extremely careful, follow the basic guidelines by washing your hands frequently, keeping at least a 6 feet distance from others, doing everything you can to stop the virus from spreading and please above all stay home if you can!” he wrote.

“Together we can fight this virus and stop the current worldwide crisis, so we can hopefully return to our normal daily lives very soon,” he wrote. “Please follow your local government’s guidelines and regulations for staying safe and protecting not just yourselves but our entire community.”

He is among a growing list of celebrities, actors and sports stars to announce they tested positive for the virus. Others who have disclosed their status include the actors Tom Hanks and his wife, Rita Wilson, and the N.B.A. stars Kevin Durant and Rudy Gobert.

This month, The Royal Opera House in London announced that Mr. Domingo had withdrawn from his upcoming performances there this summer.

The announcement came after Mr. Domingo apologized to women who had accused him of sexual harassment.

“I respect that these women finally felt comfortable enough to speak out, and I want them to know that I am truly sorry,” he said.