According to local media reports, the 40-year-old man was found dead in his room at the four-star Hotel Continentale on Saturday morning after staff alerted the police.
He is reported to have arrived in the Italian city on Friday night with the 43-year-old woman, thought to be his partner, who is being treated at the city’s Careggi hospital.
Local police and forensic teams were seen at the luxury hotel on Saturday, which is located a short walk away from the Ponte Vecchio in the historic centre of Florence, and investigations are reportedly under way.
When approached by the PA news agency, hotel staff were unable to provide any information regarding the incident.
A Foreign, Commonwealth and Development Office (FCDO) spokesperson said: “We are in touch with the Italian police following the death of a British man in Florence.”