Donald Trump has won Pennsylvania and its prize of 20 electoral votes.
Trump's stunning victory in the key battleground state gives him 264 electoral votes.
It takes 270 electoral votes to win the presidency. Trump's opponent, Hillary Clinton, has 215.
Pennsylvania last voted for a Republican for president in 1988. Trump repeatedly campaigned there, believing his populist message would resonate with the state's working-class voters.
Clinton long viewed the state as a key part of her "firewall" and rallied in Philadelphia with President Barack Obama on Monday night. The Democrats also held their nominating convention in the city.