The two aircraft crashed over the central town of Inca at 1:35 pm (1135 GMT), the regional Balearic Islands government said on its Twitter account.
Everyone aboard the two aircraft — two on the plane and five on the helicopter — perished in the crash, a police spokesman said.
A couple and their two children, reported to be of German nationality, were aboard the helicopter along with the pilot who was named locally as Italian Cedric Leon.
The pilot of the plane was named as Juanjo Vidal from Valencia, who died alongside his friend and passenger Gustavo Serrano.
Police said the two aircraft crashed into a field, in what was described as the worst plane crash in Mallorca since 1959.
Mallorca and the other Balearic Islands are popular with both Spanish and foreign tourists, especially in the summer season.
— Catalunya Informació (@Catinformacio) August 25, 2019
Spanish Prime Minister Pedro Sanchez expressed condolences to the victims' families, and said in a tweet that he was “following the news from… Mallorca with concern.”
Siguiendo con preocupación las informaciones que nos llegan desde Inca, en Mallorca. Mi solidaridad y cariño para las familias de las víctimas que han perdido la vida es este trágico accidente, entre ellas un menor de edad. https://t.co/CB9zSmLM35
— Pedro Sánchez (@sanchezcastejon) August 25, 2019