His 40-year career included the hits Twenty-Four Hours From Tulsa and Something's Gotten Hold Of My Heart.
A spokesman for South Wales Police said: "We've had a report of a death. It is not believed to be suspicious. We had the call just before 10.10am. The body, which has not been formally identified yet, was found at the Hilton Hotel in Cardiff."
Pitney played St David's Hall in Cardiff on Tuesday night and was due to perform in Bristol on Wednesday night.
In an interview at Christmas he spoke of his excitement attaking his show around the UK on a 23-date tour which was due to endlater this month.
He denied it was a gruelling schedule, saying: "I take care of myself. I can finish up the tour no problem whatsoever. I love doing what I'm doing - to pick and choose where I want to go and what I want to do."
Mark Howes, of Pitney's management company In Touch Music, said the singer was found dead in his bed by his tour manager.
Pitney rose to fame in the Sixties and was introduced to a newgeneration of fans in 1989 when he duetted with Marc Almond onS omething's Gotten Hold Of My Heart. The single gave Pitney his first UK number one - 22 years after its first release.
He had 11 top 10 hits in this country including That Girl Belongs To Yesterday and Looking Thru The Eyes of Love.
It's really sad that such a great singer and songwriter has died so early. I love his songs. I will upload the ones I have later cause you really have to listen to them.
Edit: Right-click and save-as
01. Every Breath I Take
02. Hello Mary Lou
03. It Hurts To Be In Love
04. Looking Through The Eyes Of Love
05. Man Who Shot Liberty Valance
06. Only Love Can Brake A Heart
07. She's A Heartbreaker
08. Something's Gotten Hold Of My Heart (with Marc Almond)
09. Something's Gotten Hold Of My Heart
10. That Girls Belongs To Yesterday
11. Town Without Pity
12. True Love Never Run Smooth
13. Twenty Four Hours From Tulsa
14. You've Lost That Lovin' Feelin
x-posted to freeupyourmind