With time running out in an extra period, Cesc Fabregas found Andres Iniesta in the penalty area and the Spanish midfielder took a touch before shooting it past goalie Maarten Stekelenburg, handing Spain its first World Cup championship.
It was the third time the Netherlands reached the final without coming away with the championship.
The game in Johannesburg, South Africa, was a physical and bruising affair. The Netherlands was playing with 10 men after John Heitinga was sent off with his second yellow card of the match in the 111th minute, setting up Spain's goal.
Both teams seemed flat and uninspired in the first half. The Netherlands' strategy to nullify Spain's creative mid-fielders worked well, producing few legitimate scoring chances for either team.
The Dutch defense played rough, with hard fouls given by Nigel de Jong, Robin van Persie and Mark van Bommel earning yellow cards.
The tight play continued in the second half. Casillas made a brilliant leg save in Robben's left-footed shot in the 62nd minute.