The Festival dei Due Mondi (Festival of the Two Worlds) is an annual summer music and opera festival held each June to early July in Spoleto, Italy, since its founding by composer Gian Carlo Menotti in 1958. It features a vast array of concerts, opera, dance, drama, visual arts and roundtable discussions on science.

The "Two Worlds" in the name of the festival comes from Gian Carlo Menotti's intention to have the worlds of American and European culture facing each other in his event; this concept would then be strengthened by the fact that it was held in conjunction with its "twin", the Spoleto Festival USA held annually in May/June in Charleston, South Carolina. That twinning lasted some 15 years and, after growing disputes between the Menotti family and the board of Spoleto Festival USA, in the early 1990s a separation occurred.