Flavio, re de' Longobardi (Flavio, King of the Lombards, HWV 16) is an opera in three acts by George Frideric Handel. The Italian-language libretto was by Nicola Francesco Haym, after Matteo Noris's Il Flavio Cuniberto. It was Handel's fourth full-length opera for the Royal Academy of Music. Handel had originally entitled the opera after the character of Emilia in the opera.
Handel completed the score only seven days before the premiere, at the King's Theatre in the Haymarket on 14 May 1723. There were eight performances in the premiere run. The work was revived on 18 April 1732, under the direction of the composer, for four performances.