Saudi Arabia has executed the prominent Shia cleric Sheikh Nimr al-Nimr, the interior ministry said.
He was among 47 put to death after being convicted of terrorism offences, it said in a statement.
Sheikh Nimr was a vocal supporter of the mass anti-government protests that erupted in Eastern Province in 2011, where a Shia majority have long complained of marginalisation.
His arrest two years ago, during which he was shot, triggered days of unrest.
Sheikh Nimr's death sentence was confirmed in October.
His brother said he was found guilty of seeking "foreign meddling" in the kingdom, "disobeying" its rulers and taking up arms against the security forces.
Shia-led Iran - the main regional rival of Sunni-ruled Saudi Arabia - previously warned that executing Sheikh Nimr would "cost Saudi Arabia dearly".
Protests broke out in early 2011 in the oil-rich Eastern Province in the wake of the Arab Spring.
Saudi authorities deny discriminating against Shia and blame Iran for stirring up discontent.
Saudi Arabia carried out more than 150 executions last year, the highest figure recorded by human rights groups for 20 years.
(BBC)