A person with whom he was in contact yesterday tested positive for Covid-19 today,” the palace said in a statement, adding that the 52-year-old monarch had suspended all official activities for 10 days.
“In conformity with health rules, he will observe a preventative quarantine for 10 days starting now,” the statement said.
Queen Letizia and the royal couple's daughters Leonor and Sofia “may continue their activities normally”, it added.
Crown Princess Leonor, 15, self-isolated for two weeks in September after a Covid-19 infection was detected among her classmates. She later tested negative.
Spain is among the countries hardest hit by the coronavirus pandemic with more than 1.5 million cases and more than 43,000 deaths.