Rinaldo is an Italian opera by George Friderich Handel. The libretto was written by Giacomo Rossi based on episodes of Torquato Tasso's Gerusalemme liberata ("Jerusalem Delivered"). Armida is the enchantress who holds Rinaldo under her spell in a magical palace that is an illusion. Without him, affairs are going badly (offstage) for the crusaders. The pastoral idyll, Armida's hate for the crusaders turned to love for one Crusader, and the call of duty that leaves Armida abandoned, all appealed to Baroque and Rococo (illustration, right) artists.

Rinaldo was the first opera Handel produced for London and the first Italian opera composed specifically for the London stage. It was first performed in the Haymarket Theater on 24 February 1711. It was a great success thanks in part to the participation of two of the leading castrati of the era, Nicolo Grimaldi ("Nicolini") and Valentino Urbani. Like Handel's other works in the opera seria genre, Rinaldo fell into oblivion for two hundred years. However, starting in the 1970s, it has been revived regularly and has become part of the standard operatic repertoire. There are a several recordings of it, and it is regularly performed. In 1984, a production of Rinaldo was mounted with the American mezzo-soprano Marilyn Horne in the title role at the Metropolitan Opera, the first Handel opera ever performed at the Met. In more recent years, the opera has been revived for the counter-tenor David Daniels, who also participated in a complete recording of it with mezzo-soprano Cecilia Bartoli and Christopher Hogwood conducting the Academy of Ancient Music.