The victory in an excellent final full of attacking intent meant they become the first team to win back-to-back European Championships - either side of their maiden World Cup triumph in 2010.
Spain attacked from the start and went ahead after 14 minutes with a David Silva header and doubled the lead four minutes before halftime when left back Jordi Alba galloped past a frozen Italian defence onto a precise Xavi pass before planting a confident shot beyond Gianluigi Buffon.
Italy's slim hopes of a comeback disappeared when third substitute Thiago Motta pulled a hamstring, leaving his side down to 10 men for the final half-hour.
Fernando Torres became the first player to score in two Euro finals when he made it 3-0 six minutes from time and fellow substitute Juan Mata added the fourth.
