At least six people are believed to have died when torrential rainstorms deluged the town of Sant Llorenc, about 40 miles east of the capital, Palma, on Tuesday evening.
The deputy mayor of the town, Antonia Bauza, confirmed to Cadena SER radio that two of the victims were British, while two others killed in the town were locals.
Two further victims died in the town of S’illot, authorities said.
The Foreign Office said it was “urgently seeking updates” from their Spanish counterparts about the fate of any British people stranded in the area.
The two British victims, believed to be a couple, were reportedly in a taxi when they were caught in a flash flood.
The Foreign Office said in a statement: “We are in contact with the Spanish authorities responding to flooding in Majorca, and urgently seeking updates from them.”
Hundreds of displaced residents are seeking shelter in emergency relief centres, while soldiers have been sent to assist the rescue effort, Spanish authorities said.
The Spanish weather agency reported around 8in (20.3cm) of rain fell in four hours on Tuesday