Emergency services were called to reports that the man got into difficulty near the Pico Gallinero peak in the Aragonese Pyrenees mountains, close to Spain's border with France, at around 1.30pm on Thursday.
A police helicopter and officers from the Greim Mountain Rescue Team responded and were said to have found two people performing CPR on the 50-year-old man, who has not been named.
He died as a result of what was described as severe injuries.
The deceased was flown away from the scene by helicopter, local media outlet Cadena Ser reported.
Local police said they have opened an investigation and a post-mortem would take place.
The event was attended by the Huesca Civil Guard, which also had to evacuate two climbers from Huesca in the Ordesa and Monte Perdido National Park and a Madrid hiker in the Collado de Añisclo on Wednesday.
The Pico Gallinero peak, more than 8,000ft high, is popular with people who take part in extreme sports such as paragliding and rock climbing.
It is about 28km (17 miles) south of the Pic de Sauvegarde, where British woman Esther Dingley went missing in November 2020.
Her remains were found in July the following year. She died instantly after falling 100ft from a rocky ledge, officials said.
The Independent has contacted the Foreign, Commonwealth and Development Office for comment.