There are unconfirmed reports that two Britons are among the casualties as the floods hit the Sant Llorenc area early on Wednesday morning.
The rain was so heavy a river burst its banks.
A spokeswoman with the regional emergency service said two British nationals and a Dutch woman were among the victims, but she couldn't confirm whether six more people were still missing at midday as local media reported.
The island was hit by devastating floods overnight, with torrential rainstorms hitting the town of Sant Lorrenc, about 40 miles east of the capital Palma.More news: You Need To Watch Cardi B's OTT American Music Awards Performance
People walk along the damaged waterfront after a storm on the island of Mallorca, Spain, on October 10, 2018.
Hundreds of displaced residents are in emergency shelters, and around 80 soldiers are set to join more than 100 rescuers who are working in the area.
The weather agency, AEMET, said more heavy rainfall is expected Wednesday in eastern and southern parts of the Iberian peninsula.
Spanish authorities say that a total of five people have died, and a further 12 are missing.More news: Thomas Rhett's American Music Awards flashy suit contains hidden tribute
At least 220 millimetres of rain are believed to have fallen in the region, flooding homes, roads and fields.
The Spanish Prime Minister Pedro Sánchez tweeted: "My solidarity and support goes out to the families and friends of victims and all those affected by these tragic floods".
Sanchez was planning to travel to the area later on Wednesday, his office said.
A minute's silence has been held by the Spanish parliament to remember the victims. Streets in towns near Malaga on the Costa del Sol experienced flood water which was several feet deep.More news: Huawei Mate 20 Pro images reveal awesome 'waterdrop' style notch screen
- Saudi government planned Jamal Khashoggi hit: NY Times
- 'Pet Sematary' Remake Gets A Creepy Resurrection In Chilling Trailer
- Hurricane Michael takes aim at Florida Panhandle, prompting evacuations
- PSN ID Change Feature Announced, In PlayStation Preview Program Now
- Apple Watch Series 4 Crashing And Rebooting Due To Daylight Saving Bug
- Melania Trump On Me Too: We Should Support Men, 'Not Just Women'
- Jimmy Butler Returns To Practice: "You Can't Win Without Me"
- Google Lens Now Built Into Pixel 3 Camera
- Rock used as a doorstop for decades is actually a $100,000 meteorite
- William and Kate to attend mental health summit