In the process, the PNP shoved the Andrew Holness-led Jamaica Labour Party into the history books, as it became the first political party to only spend one term in office.
The result means a return by veteran PNP politician Portia Simpson Miller to the post of prime minister.
Current PM Andrew Holness said it was a "humbling" defeat for his Jamaica Labour Party.
The snap election was called earlier this month by Mr Holness who succeeded Bruce Golding as JLP leader in October.
Despite forecasts of a close race, preliminary official results showed that Mrs Simpson Miller's party had won 41 seats out of 63 for a big majority in parliament.
Mrs Simpson Miller, 66, was first elected to parliament in 1976 and became Jamaica's first woman prime minister in 2006-07.
She will face deep problems, with debt running at approximately 130% of GDP and unemployment at more than 12%.
At her party headquarters in Kingston, Mrs Simpson Miller thanked her supporters.
"I am humbled as I stand before you and I wish to thank the Jamaican people for their love, for their support and for giving the People's National Party and the leader of the party her own mandate," she said.
Conceding victory, Mr Holness, in office for just over two months, said he wished the new government well.
"There are challenges that they will face, challenges that we are quite well aware of. And we hope for the benefit of the country and for the interest of the people of Jamaica that they will do a good job," he said.
Monitors said polling got off to a relatively smooth start on Thursday in a country where previous elections have been marred by violence.
Later some glitches were reported, such as fingerprint scanners working intermittently, leading to long queues at some of the country's polling stations.
But Lisa Shoman, the head of the observer mission for the Organization of American States, said her 25-member team has not reported "any disturbances or any issues that would cause us any serious concern".
The BBC's Nick Davis in Kingston says while violent crime used to dominate election campaigns, the economy and unemployment have now become the main issues.
Mr Holness stressed the JLP's record in reviving an economy which he said was badly managed during the PNP's long years in office.
However the PNP said the JLP itself was guilty of economic mismanagement and has allowed the country's debt to balloon.