Ugo, re d'Italia (Hugo, King of Italy) is an unfinished opera by Gioachino Rossini that was abandoned when the composer and his wife, Isabella Colbran, were staying in London from December 1823 until July of the following year.

[4] Leaving behind the "preliminary workings and a bond for £400 with Benelli's bankers" (as surety for its completion),[1] Rossini and Colbran left England on 25 July 1824, never to return.

[5] Following the success of Semiramide in 1823, Rossini was able to spend the summer of that year in Italy, but by mid-1823, the impresario Giovan Battista Benelli (who had taken over the lease at the King's Theatre) prevailed.

A season was planned for 1824, part of which involved an obligation to complete a two-act opera to be called La figlia dell'aria.

[5] Throughout the month following their arrival, Rossini was feted by the musical establishment and by Parisian society, all with the aim of enticing him into further involvement in their city.

Porter notes that it never seems to have surfaced while Osborne states that "two packets of paper and a residual sum of £321.9s.0d [Three hundred and twenty one pounds, nine shillings] were reported to have been handed over to Rossini [in 1831].

[1] There are some sketches of this work preserved in the manuscript of Ermione which is held in the Bibliothèque nationale de France in Paris.