Landslide victory for Orban in Hungarian elections
The resounding two-thirds victory granted Orban's Fidesz and their coalition partners the "supermajority" they needed to make constitutional changes.
The 54-year-old is a strong Eurosceptic and took an anti-immigration stance in his campaign.
He appeared in front of supporters at Fidesz's headquarters on the Danube in Budapest just before midnight to declare his victory.
"When you get a result like this," said Orban, "you must remember a wise saying: be modest because now you have a reason to be".
In his acceptance speech, Orban rejected accusations of authoritarianism.
"Our country has not yet reached where it wants to be," he said. "But it is on it's chosen path. We will continue together on this path."
"Hundreds celebrated the third consecutive win of FIDESZ," said Euronews's Budapest correspondent Attila Magyar. "They and even Orban may not have expected this success. The question now is if the prime minister will change his rhetoric or hold on to his anti-Brussels approach."
Some polling stations, which were meant to close at 7 pm local time, stayed open hours later due to queues.
Voter turnout was around 69% - nearly a record for the country.
Hungary's right-wing Jobbik party came a distant second prompting the resignation of Jobbik's chairman Gabor Vona.
"I respect the decision of the voters, even if it hurts and feels bad, even if one expected a lot more support for one's party. But we have to accept as part of life and part of democracy when things go differently to what we would have liked," Vona said at a late-night news conference.