Hotel staff found the man and woman, believed to be in their late 30 or early 40s, at the Double Tree by Hilton Majestic Hotel and Spa in Harrogate on Tuesday.
They were pronounced dead after police were called to the £150 a night hotel in Springfield Avenue at 10.20pm.
North Yorkshire officers have not yet named the couple, from the London area, but said they were not looking for anyone in connection with their deaths.
Det Supt Wayne Fox said it was believed to be an isolated incident.
“We were called at around 10.20pm on Tuesday 4 May by hotel staff at the Majestic Hotel to a report that the bodies of a man and a woman had been located in a hotel room.
“On arrival, a man and a woman, both in their late 30s/early 40s from the London area, were pronounced dead at the scene by colleagues from the ambulance service. Their families have been informed and are being supported by specially-trained officers.
“A detailed investigation is under way looking into the circumstances of both deaths. We can confirm that we are not looking for anyone else in connection with the deaths and would like to reassure the local community that we believe that this is an isolated incident.”
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