Its stature is built on its geographical size (twice that of France and Germany combined), its prestige as the custodian of the birthplace of Islam and its colossus status as an oil producer - with a quarter of the world's proven reserves under its deserts.
Its importance as an oil exporting nation has made economic interdependence with the West - where the main consumer demand is found - a necessity.
This, in turn, has led to strong political and military relationships that at times have been a source of awkwardness for both sides.
It stands out for its espousal of a puritan version of Sunni Islam, including harsh punishments such as public beheadings, and its restrictions on women.
Population 28.7 million
Area 2.24 million sq km (864,869 sq miles)
Major language Arabic
Major religion Islam
Life expectancy 73 years (men), 76 years (women)
Currency Riyal
Head of state, prime minister: King Salman bin Abdulaziz al-Saud
The Al Saud dynasty holds a monopoly of political power. Saudi Arabia was established in 1932 by King Abd-al-Aziz and he has been succeeded by various sons.
King Salman bin Abdulaziz al-Saud ascended the throne in January 2015 following the death of his half-brother, King Abdullah.
He has been part of the ruling clique of princes for decades and is thought likely to continue the main thrusts of Saudi strategic policy, including maintaining the alliance with the United States and working towards energy market stability.
Saudi investors are major players in the pan-Arab TV industry, but the country has one of the region's most tightly-controlled media environments.
The government openly acknowledges that widespread internet filtering takes place. It targets "pornographic", Islam-related, human rights and political sites.
Saudi Arabia has the highest per-capita YouTube use of any country in the world. It is reportedly home to more than 40% of all active Twitter users in the Arab region.
Some key events in Saudi Arabia's history:
1932 - The areas controlled by King Abd-al-Aziz are unified under the name Kingdom of Saudi Arabia.
1938 - Oil is discovered and production begins under the US-controlled Aramco (Arabian American Oil Company).
1960 - Saudi Arabia is a founding member of Opec (Organisation of Petroleum Exporting Countries).
1973 - Saudi Arabia leads an oil boycott against the Western countries that supported Israel in the October War against Egypt and Syria. Oil prices quadruple.
2001 11 September - 15 of the 19 hijackers involved in attacks on New York and Washington are Saudi nationals.
2011 - As ''Arab Spring'' protests ripple across the region, Saudi troops participate in crackdown on unrest in Bahrain.
2015 March - Saudi Arabia launches campaign of air strikes against Houthi rebels in Yemen.
The Kingdom of Saudi Arabia is one of the main players in the Arab world.