Engelbert Humperdinck has tested positive for coronavirus.
The singer, 84, asked for “prayers, good energy, love and support to be sent our way” after Covid-19 “found a way into our home”.
His agent said on Wednesday he is currently asymptomatic.
Humperdinck, who is at his home in Los Angeles, said the positive tests came after “nearly a year of an abundance of caution and care”.
In a series of tweets on Tuesday night, he added: “Now we must not let a positive result bring a negative mindset but I must say I could use your help in this department.
“We are asking for prayers, good energy, love and support to be sent our way.”
He said his daughter had brought “cases of photographs to reflect upon and keep us strong through our recovery”.
He added: “My biggest ‘ask’ is for my darling wife, Patricia (Popea).
“She has been through so much and does whatever it takes. She is an unbelievable woman of strength.
“Please also keep our wonderful caregivers in your prayers.”
Humperdinck topped the UK singles chart with his hits Release Me and The Last Waltz in the 1960s.
He also represented the UK at the Eurovision Song Contest in 2012 with the song Love Will Set You Free, finishing second last.
A number of famous faces including TV presenter Sharon Osbourne and actors Tom Hanks, Idris Elba and Bryan Cranston have previously shared their experiences of contracting coronavirus.