Spaniards are a nation and ethnic group native to Spain, sharing a common Spanish culture and speaking one of the national languages of Spain, including most numerously the Castilian Spanish language, as a mother tongue.

Within Spain there are a number of nationalisms and regionalisms, reflecting the country's complex history and diverse culture.

Although the official language of Spain is today commonly known as "Spanish", it is only one of the national languages of Spain, and is less ambiguously known as Castilian, a standard language based on the medieval romance speech of the early Kingdom of Castile in north-central Spain and the Mozarabic dialect of the Taifa of Toledo, which was incorporated by the former in the eleventh century.

There are several commonly spoken regional languages, most notably Basque (a Paleohispanic language), and Catalan and Galician (both Romance languages like Castilian). There are substantial populations outside Spain with ancestors who emigrated from Spain and who share a Hispanic culture; most notably in Hispanic America.

The Roman Republic conquered Iberia during the second and first centuries BCE.

As a result of Roman colonization, the majority of local languages, with the exception of Basque, stem from the Vulgar Latin.

The Germanic Vandals and Suebi, with part of the Iranian Alans, conquered the peninsula in CE 409. 

The Iberian Peninsula was  brought under the rule of the Arab Umayyads in 711 and by the Berber North African dynasties the Almohads and the Almoravids in the eleventh and twelfh centuries.

Following the eight centuries-long Reconquista, the modern Spanish state wais formed with the union of the Kingdoms of Castille and Aragon, the conquest of the last Muslim kingdom of Granada and the Canary Islands in the late fifteenth century.

The Kingdom of Navarre is conquered also In the early sixteenth century.

As Spain expands its empire in the Americas, religious minorities in Spain are either converted or expelled and the Catholic church fiercely persecutes heresy during a period known as the Spanish inquisition.

In parallel, a wave of emigration begins with two hundred and forty thousandf Spaniards voyaging to the Americas.

They are joined in the next century by another four hundred and fifty thousand[.

With the conquest of Mexico and Peru, these two regions become the principal destinations of Spanish colonial settlers in the sixteenth century.

In the period 1850–1950, three and a half million Spanish leave for the Americas, particularly Argentina, Uruguay, Mexico, Brazil, Chile, Venezuela, and Cuba.

Spain is home to one of the largest communities of Romani people (commonly known by the English exonym "gypsies", Spanish: gitanos).

The Spanish Roma, which belong to the Iberian Kale subgroup (calé), are a formerly-nomadic community, which spread across Western Asia, North Africa, and Europe, first reaching Spain in the fifteenth century.

The population of Spain is becopming  increasingly diverse due to recent immigration.

From 2000 to 2010, Spain has among the highest per capita immigration rates in the world and the second highest absolute net migration in the World (after the USA) and immigrants now make up about ten percent of the population.

Nevertheless, the prolonged economic crisis between 2008 and 2015 significantly reduces both immigration rates and the total number of foreigners in the country, Spain becoming once more a net emigrant country.