Rock in Rio is a series of music festivals held in three cities: Rio de Janeiro in Brazil, Lisbon in Portugal and Madrid in Spain. In 2013, Buenos Aires, Argentina, will be the fourth.

Rock in Rio has been the largest music festival in the world, with 1.5 million people in the first edition, 700,000 in both the second and fourth editions, about 1.2 million in the third, and about 350,000 people in each of the 3 Lisbon editions.