The young man got up close to the Prime Minister, reportedly asking to take a photograph, before unleashing his left fist into the side of Rajoy's head.
The punch knocked Rajoy's glasses off of his face, leaving the leader of the People's Party bruised but otherwise "feeling good," he later said in a tweet.
The 17-year-old attacker was later shown being taken away in handcuffs by security guards.
Rajoy had been speaking to a large crowd in the northwestern city of Pontevedra, ahead of the country's general election on Sunday.
Watch the video below:
Watch the video below:
