Crowds of white-clad protesters tried to block the vehicle carrying the 42-year-old Harvard-educated economist after he made a defiant speech, said an emotional farewell to his family, and gave himself up to soldiers.
Opposition leaders hope Mr Lopez's arrest will galvanize street demonstrations against President Nicolas Maduro, though there is no immediate sign the protests will topple the socialist leader.
The protest leader told supporters: "I am handing myself over to an unfair justice system. May my imprisonment serve to wake the people up."
The crowd lifted his wife up to give him a final embrace and hang a crucifix around his neck.
Minutes later, he surrendered to military officers, pumping his fist and then stepping into the military vehicle.