The term Spanish people (or Spaniards) has two distinct meanings: Traditionally, it applies to people native to any part of Spain. More recently, it has also come to have a legal meaning, referring to people who hold Spanish citizenship.

Within Spain there are a number of nationalisms and regionalisms, reflecting the country's complex history. The official language of Spain is Spanish (also known as Castilian), a standard language based on the mediaeval dialect of the Castilians of north-central Spain. There are several commonly spoken regional languages. With the exception of Basque, the languages native to Spain are Romance languages.

There are substantial populations outside Spain with ancestors who emigrated from Spain; most notably in Latin America.

The earliest modern humans inhabiting Spain are believed to have been Neolithic peoples who may have arrived in the Iberian Peninsula as early as 35,000­–40,000 years ago. In more recent times the Iberians are believed to have arrived or developed in the region between the 4th millennium BC and the 3rd millennium BC, initially settling along the Mediterranean coast. Celts settled in Spain during the Iron Age. Some of those tribes in North-central Spain, which had cultural contact with the Iberians, are called Celtiberians. In addition, a group known as the Tartessians and later Turdetanians inhabited southwestern Spain and who are believed to have developed a separate civilization of Phoenician influence. The seafaring Phoenicians, Greeks, and Carthaginians successively founded trading colonies along the Mediterranean coast over a period of several centuries. The Second Punic War between the Carthaginians and Romans was fought mainly in what is now Spain and Portugal.