The three clubs will play each other in a round-robin group, with Inter against Bayern held in Milan, Real facing Inter in Madrid and Bayern hosting Real in Munich.
Proceeds from the fixtures will be donated to medical facilities in Italy and Spain, two of the world’s worst-hit countries by the coronavirus pandemic.
The aim is “to send out a message of solidarity and fraternity to the people of Europe”, said a statement from Real Madrid.
Dates for the tournament have not been decided. The timing will “depend on the match calendar and when football can be played in front of fans again”, the clubs said.
Bayern will invite 5,000 nurses, carers and doctors to the Allianz Arena for their match against Real Madrid.
“Nurses, carers and doctors in particular are doing an outstanding job for society at the moment,” said Bayern chairman Karl-Heinz Rummenigge. “We, the three clubs, want to show these heroes our appreciation, respect and gratitude.”
“The great commitment of all healthcare workers has been essential to allow us to look to the future,” said Inter president Steven Zhang.
“With this initiative we want to thank them and celebrate their work and at the same time send a message of unity and solidarity between nations.”