The term southern Europe, at different times, has had different meanings, providing additional political, linguistic and cultural context to the definition in addition to the typical geographical, phytogeographic or climatic approach. Most coastal countries in the United Nations-designated southern Europe border the Mediterranean Sea. Exceptions are Portugal which has only Atlantic coastline, Serbia and the Republic of Macedonia, which are landlocked, and Bulgaria, which borders the Black Sea.

Geographically, southern Europe is the southern half of the landmass of Europe. This definition is relative, with no clear limits.

Countries geographically considered part of southern Europe include:

For its official works and publications, the United Nations Organization groups countries under a classification of regions. Southern Europe, as defined by the United Nations (the sub-regions according to the UN), comprises the following countries and territories:

As of 2009, there were 163,865,210 people living in southern Europe with an average population density of 74 inhabitants per square kilometer: