Vicente del Bosque's team became the first side to successfully defend a European Championship title, as well as the first to win three consecutive major tournaments after their triumphs at Euro 2008 and the 2010 World Cup.
Accused in some quarters of having lost their ability to excite, Spain produced a thrilling demonstration of attacking soccer to confirm beyond doubt that this remains a golden age for Spanish soccer.
Andres Iniesta and Xavi were the architects of victory, playing key roles in goals by David Silva, Jordi Alba and Fernando Torres, who teed up fellow substitute Juan Mata for Spain's fourth.
"After we scored the first goal, Italy were dangerous, but we reacted well," said Spain coach Del Bosque.
"We had possession of the ball, we put pressure on them, and there was depth to our play. So we're very happy.
"This success in Spanish [soccer] is something historic, and now we have to look to the future and try to qualify for the 2014 World Cup in Brazil."
The match-winner in the Euro 2008 decider against Germany, Torres became the first player to score in two European Championship finals, while it was the most handsome winning margin in a final in the tournament's history.
Italy played the last half an hour with 10 men after third substitute Thiago Motta was forced off by injury moments after coming on, as the momentum that had taken the Azzurri past Germany and England in the knockout rounds disappeared.
"We came up against a terrific side," admitted Italy coach Cesare Prandelli.
"They're world champions. Obviously, when you go down to 10 men, the game's over."
The star of the semifinal win over the Germans, Mario Balotelli endured a fruitless evening while Andrea Pirlo was upstaged by the pass masters in the Spanish midfield.
"Against Spain, you accept losing more easily," said Italy captain Gianluigi Buffon. "It was a great adventure. In a final, you have to win but today we played against a team of incredible quality."
Dropped for the semifinal against Portugal, Cesc Fabregas returned to Spain's starting line-up to occupy the 'false nine' role he had taken up against Italy in the 1-1 draw between the sides in Group C on June 10.
Prandelli also made one change to his starting XI, with Ignazio Abate replacing Federico Balzaretti at right-back after missing the semi-final win over Germany due to muscle fatigue.
It was quickly apparent that Spain had a point to prove and in the 10th minute there was a glimpse of the pin-sharp attacking soccer that had eluded them in recent matches, as Xavi exchanged passes with Fabregas before rifling a shot narrowly over.
Four minutes later the deadlock was broken, Iniesta threading a superb pass down the inside-right channel to Fabregas, who slipped around Giorgio Chiellini before cutting the ball back for Silva to head home.
Chiellini's evening lasted barely more than 20 minutes, as the Juventus defender was forced off after landing awkwardly and had to be replaced by Balzaretti.
Having being eclipsed by Iniesta in recent matches, Xavi proved that reports of his demise are grossly premature by creating Spain's second goal four minutes before half-time.
The 32-year-old maestro collected a pass from Alba and then delayed his pass supremely before freeing his future Barcelona team-mate to run in and place the ball past Buffon for his first international goal.
Prandelli replaced Cassano with Antonio Di Natale at the interval and the Udinese man made an immediate impact, heading just over from Abate's centre and then obliging Casillas to save after ghosting in behind Spain's defence.
At the other end, Buffon thwarted Fabregas after the Barcelona man weaved his way past Balzaretti and Leonardo Bonucci, who was lucky not to concede a penalty when he appeared to block Sergio Ramos' header with his arm.
Italy's hopes of a comeback evaporated in the 62nd minute, as Motta was carried off on a stretcher with an apparent hamstring injury just five minutes after replacing Riccardo Montolivo, leaving Prandelli's side with 10 men.
The game dipped in intensity until the arrival of Torres, who rolled home Spain's third from Xavi's pass in the 84th minute before teeing up Chelsea teammate Mata for an 88th-minute tap-in. – Sapa-AFP