Monitoring groups say the kingdom executed at least 157 people in 2015
Saudi Arabia has executed 47 people convicted of terrorist offences including a prominent Shia cleric.
Nimr al Nimr was a driving force behind the protests in the east of the Sunni-ruled kingdom in 2011.
His death has been widely condemned and there are fears it may spark fresh unrest among Saudi's Shia minority and in neighbouring Bahrain.
However, the 56-year-old's brother has called for a "peaceful" response to the news of his execution.
The list of those beheaded did not include Nimr's nephew, Ali al Nimr, who was 17 when he was arrested after the 2011 demonstrations.
Most on the list were detained after a series of attacks by al Qaeda between 2003 and 2006 in which hundreds of people were killed.
In a statement the Interior Ministry said the 47 had been convicted of adopting the radical "takfiri" ideology, joining "terrorist organisations" and implementing various "criminal plots".
All but two - an Egyptian and a Chadian - were Saudi nationals.
The executions have been denounced by Shia-dominated Iran, Saudi Arabia's main rival in the Middle East.
It warned that the death of Nimr would cost it "dearly", while one Iranian MP predicted it would "set the region on fire".
A leading Iranian cleric, Ayatollah Ahmad Khatami, has predicted the repercussions will bring down the Saudi ruling family.
"I have no doubt that this pure blood will stain the collar of the House of Saud and wipe them from the pages of history," he was quoted as saying by the Mehr news agency.
Lebanon's Supreme Islamic Shia Council has described Nimr's execution as a "grave mistake".
Nimr's family said they were shocked but did not want it to result in further bloodshed.
His brother, Mohammed al Nimr, told Reuters: "Sheikh Nimr enjoyed high esteem in his community and within Muslim society in general and no doubt there will be reaction.
"We hope that any reactions would be confined to a peaceful framework.
"No one should have any reaction outside this peaceful framework. Enough bloodshed."
Last year 157 people were executed in Saudi Arabia, compared to 90 in 2014.
Speaking in November, James Lynch of Amnesty International said “beheading or otherwise executing dozens of people in a single day would mark a dizzying descent to yet another outrageous low for Saudi Arabia, whose authorities have continued to show stone-faced cynicism and even open defiance when authorities and ordinary people around the world question their sordid record on the use of the death penalty".