Spanish Prime Minister Mariano Rajoy and the leaders of France, Italy, Portugal, Greece, Cyprus and Malta will gather on April 10th at El Pardo palace outside Madrid, his office said on its website.
"The main goal of this meeting is to discuss all the work that is being carried out to have good Brexit negotiations," it said.
The meeting of the leaders will be the third by the group following gatherings in Athens in September and Lisbon in January.
Southern European leaders have sought at past meetings to forge a common front on growing challenges, from the refugee crisis to Brexit, and to counter the influence of nations in northern Europe within the bloc.
Rajoy had announced at the Lisbon meeting that Spain would host the next gathering of the group, without giving a date.
The announcement of the date of the gathering coincided with Britain's formal notification that it was beginning the process of quitting the EU.