The 40-year-old man was found dead in his room at the four-star Hotel Continentale on Saturday morning, according to local media reports, after staff alerted the police.
He should have arrived in the Italian City on Friday night with the 43-year-old woman believed to be his partner, who is being treated at the city’s Careggi Hospital.
Local police and forensic teams were seen Saturday at the luxury hotel, which is a short walk from the Ponte Vecchio in Florence’s historic center, and investigations are ongoing.
When approached by the PA news agency, hotel staff could not provide any information on the incident.
A spokesman for the Foreign, Commonwealth and Development Office (FCDO) said: “We are in contact with Italian police following the death of a Brit in Florence.”