The Count of Luxembourg is an operetta in two acts with English lyrics and libretto by Basil Hood and Adrian Ross, music by Franz Lehár, based on Lehár's three-act German operetta Der Graf von Luxemburg which had premiered in Vienna in 1909. Lehár made amendments to his Viennese score to accommodate the two-act adaptation. He also interpolated into the score three new pieces: a waltz that he had written for a commemorative performance of Der Graf in Vienna; a song from his first operetta, Wiener Frauen; and a Russian dance from the opera Tatjana.
The Count of Luxembourg opened at Daly's Theatre in London on 20 May 1911 and ran for a successful 345 performances, followed by a UK tour. The operetta starred Lily Elsie, Huntley Wright, W. H. Berry and Bertram Wallis. The opening night was conducted by Lehár and attended by King George V and Queen Mary. The Times particularly praised the singing and dancing of Elsie and Wallis, as well as Lehár's music, though the paper judged the story to be thin and improbable. It also had a good run at the New Amsterdam Theatre in New York in 1912 with the libretto further adapted by Glen MacDonaugh, and it played in Australia in 1913. There was a Broadway revival in 1930. In 1967, the BBC broadcast their own television production, conducted by David Lloyd-Jones.
An American silent film version was made in 1926. A new English language adaptation of Der Graf von Luxemburg, more closely following the original score and libretto, was produced under the name The Count of Luxembourg and recorded by New Sadler's Wells Opera in 1983. This version was revived on tour by the D'Oyly Carte Opera Company in 1997.