The ban capped a turbulent 10 day-crackdown that saw pro-government groups attack several opposition leaders.
The Governor of Miranda state, who came within a whisker of defeating President Nicolas Maduro in 2013 elections, is the latest in a number of prominent opposition politicians to be targeted by the embattled socialist leader's government.
There was no immediate response from the Maduro administration on the ban.
"I inform the country and global public opinion that I am being notified at this very moment of a BAN for 15 years", tweeted Capriles, who is now the governor of the central coastal state of Miranda. In 2008, the comptroller banned Venezuela's most renowned jailed opposition figure, Leopoldo Lopez, from holding office for a decade on corruption allegations.
Coming at a time of deep political and economic malaise in what was once one of Latin America's richest democracies, the judicial overreach was met with mass outrage - even from Venezuela's attorney general, a long time Maduro supporter.
The opposition's primary demand now is to hold the next presidential election before its scheduled date at the end of 2018 to push out Socialist President Nicolas Maduro. Yesterday's was the largest opposition demonstration the country has seen in half a year. He had been expected to fight for the presidency in 2012 but had to hand the baton over to Capriles, who lost against Hugo Chavez and then against Maduro the following year.
Saturday's protests continued a week of unrest sparked by last week's Supreme Court decision in which it assumed the role of the opposition-led congress.
Tensions have been simmering this week after tear gas and rocks flew between protesters and security forces during a major demonstration on Tuesday.
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Saturday's violence broke out when protesters gathered in the east of the city changed course at Capriles's request and headed downtown toward the government ombudsman's office.
"This thing that they just did to Capriles is the product of tyranny", said Adel Rincones, 61, who wore the uniform of Venezuela's Olympic team.
State ombudsman Tarek Saab on Thursday evening shot down a censure measure against the Supreme Court justices that had been approved by the opposition-controlled assembly this week, saying the controversial ruling had been "clarified" by the reversal of the decision.
The opposition leaders called for another protest Monday.
Local media reported Ortiz was a university student planning to emigrate from Venezuela, like many in the middle class that have fled to Colombia, Panama, Chile or the USA city of Miami to escape the economic crisis and political turmoil. The court issued a ruling March 29 that outraged the government's political opposition.
The collapse in prices for Venezuela's crucial oil exports has sapped the country's revenues, prompting shortages of food, medicine and basic goods along with a surge in violent crime.
Still, others have been motivated by the escalating political crisis and the opposition coalition putting on a more dynamic and coordinated front than usual.
Lopez was arrested in 2014, at the start of months of nationwide unrest that ultimately killed more than 40 people.