A C-101, the same type of plane used by the Spanish Air Force’s Eagle Patrol aerobatics team, was on a training flight near an airbase outside the town of San Javier.
The Spanish Defence Ministry said on Monday that a military plane had crashed into the sea in south-eastern Spain.
The pilot of the light attack aircraft was killed, a source in the Defence Ministry said, as quoted by La Sexta broadcaster.
The incident occurred at around 9.40 am local time (7.40 GMT). As soon as local emergency services received information about the crash, they mobilised boats for a rescue operation.
Following initial reports of the incident, the Defence Ministry stated that the pilot, a flight instructor, was able to eject before the crash.