Robert Bruce is an 1846 pastiche opera in three acts, with music by Gioachino Rossini and Louis Niedermeyer to a French-language libretto by Alphonse Royer and Gustave Vaëz. The plot concerns the defeat of the forces of Edward II of England by Robert the Bruce, King of Scots, and is adapted from Walter Scott's History of Scotland. The music was stitched together by Niedermeyer, with the composer's permission, with pieces from La donna del lago, Zelmira, and other Rossini operas. The work was premiered on 30 December 1846, by the Paris Opera at the Salle Le Peletier. The audience may not have noticed, but the orchestra included for the first time a recently invented instrument, which later came to be known as the saxophone.

Gioachino Antonio Rossini was an Italian composer who gained fame for his 39 operas, although he also wrote many songs, some chamber music and piano pieces and some sacred music. He set new standards for both comic and serious opera before retiring from large-scale composition while still in his thirties, at the height of his popularity.