The Harvard-educated economist has been held in a military prison since his February 18 arrest in the midst of an opposition protest rally against leftist President Nicolas Maduro, who has faced near-daily demonstrations since early February.
Thirty-nine people have died in clashes between security forces and protesters angered by soaring crime, high inflation and shortages of essential goods. Another 608 were wounded and 192 are going through the court process.
Attorney General Luis Ortega Diaz told a press conference that formal charges were brought against Lopez, leader of the Popular Will party, accusing him of inciting violence, arson, damage to property and conspiracy.
The government had until Saturday -- 45 days from Lopez's arrest -- to bring the charges or release him.
The government action stems from Lopez's public support for the student-led street protests that have rocked the country since they began February 4 in the western city of San Cristobal and spread to several other major cities, including the capital Caracas.
Lopez and some other opposition leaders are advocates of a strategy dubbed "the exit," aimed at pressuring Maduro -- the handpicked successor to late socialist icon Hugo Chavez -- to resign.
Hours after the attorney general's announcement, about 3,000 demonstrators, most of them students, hit the streets in the east of Caracas demanding Lopez be freed.
Under the slogan "Free Leopoldo," some were dressed in white, a symbol of peace, while others carried the Venezuelan flag.
One young man, who wore a homemade gas mask in anticipation of security forces firing tear gas to disperse the rally, said: "We have no weapons, just stones."
Popular Will activist Ernesto Palacios, 31, told AFP: "As a sign of respect, the government should release Leopoldo Lopez and political prisoners."
From his cell at Ramo Verde military prison, Lopez, whose picture wearing a green shirt and leaning over a small window with hands on his cell bars has been circulated on social networks, has complained about his solitary confinement.
Lopez, who had called repeatedly for Maduro's resignation, is allowed one hour of exercise outdoors and has a small television.
- Drug traffickers arrested -
Separately, Maduro announced the capture of two alleged drug traffickers he linked to the anti-government protests.
Colombian suspect Hugo Alberto Nuncira Soto, alias "Don Diego" and "El Junco," of the Los Urabenos criminal gang was arrested, Maduro said, blaming him for "guarimbas," or blocking streets with rubble.
Gabriel Alejandro Reyes Beltran of Venezuela, who is wanted by Interpol, was also arrested on charges of setting up barricades in the western city of San Cristobal where the protests began two months ago.
"Criminal gangs of Colombian drug traffickers, paramilitaries and border security forces are directly involved in the planning and execution of roadblocks," the president complained on national media.
The president also ordered an investigation into armed vigilantes who entered the campus of the Central University of Venezuela in downtown Caracas, triggering violent clashes.