Located in the Principality of Monaco, an independent sovereign city-state on the French Riviera, the second-smallest country in the world by area, only after Vatican City and bordered by France to the north, east and west, the Opera de Monte-Carlo, also known as the Salle Garnier, is an opera house, which is a completely separate part of the Monte Carlo Casino. It all started centuries ago, in the 1780s, when Charles III, the then ruling Prince of Monaco, decided to include a concert hall, capable of housing lyrical and choreographic performances, as part of the Monte Carlo Casino, to diversify the cultural life of Monaco, which the city genuinely needed.

Both the buildings of the Monte Carlo Casino and the Opera de Monte-Carlo reflect a Belle Epoque or Beautiful Age, a name given in France, referring to the time period between 1871 and 1914, which heavily influenced the architectural development of Monaco. However, although the neoclassical building of the Opera de Monte-Carlo is an extension of the Monte Carlo Casino, the Opera de Monte-Carlo is just as lavish as the Casino to which it is attached.

Designed by the reputed architect Charles Garnier, who also designed the Palais Garnier in Paris, the Opera de Monte-Carlo or the Salle Garnier was constructed in only eight and a half months and resembles almost like a smaller edition of its Paris counterpart, but with only 524 seats, compared to about 2,000 of the Palais Garnier. However, its ornate style was heavily influenced by that of the Palais Garnier. The iron beams in the roof were designed by Alexandre-Gustave Eiffel, the creator of the eponymous Eiffel Tower and also the man behind the internal structure of the Statue of Liberty. While the seafront facade of Salle Garnier resembles exactly the Palais Garnier, its sanctum opens to reveal expansive views of the marble-paved atrium, with 28 imposing Ionic columns shining in onyx-glazed splendour and its main opera hall is a sterling vision in red and gold. Apart from that, the interior of the hall is lavishly decorated with drapes of red velvet, lots of gold leaf, bronzes, friezes and crystals, along with a profusion of bas-reliefs, frescoes and sculptures.

Initially, the Salle Garnier served as the Prince's private theatre and its western entrance was reserved for the royal family, while the main public entrance to the hall was from the casino. The hall was ceremoniously inaugurated by its designer, Charles Garnier, to a well-heeled crowd on 25 January 1879, with a show featuring Sarah Bernhardt, clad in a nymph costume. Consequently, the Opera de Monte-Carlo was named, the Salle Garnier, after Charles Garnier, as a tribute to its creator.

However, as it was not originally intended for opera, but was soon frequently used for that purpose, it was remodeled in 1898–99 by Henri Schmit, primarily in the stage area, to make it more suitable for opera. Since then, the Opera de Monte-Carlo, has hosted 45 world premieres, including Hector Berlioz's La damnation de Faust in 1893 to Puccini's La Rondine in 1917, along with other prestigious concerts and exceptional ballets. However, twice in its history, the Opéra was transformed into a spectacular venue to host gala-dinners for the celebration of the centenary of Monte-Carlo hosted by Grace Kelly and Rainier III; in 1966 and the dinner reception for the royal wedding of Prince Albert II of Monaco and Princess Charlene in July 2011. Apart from that, it deviated from its role for the third time on 27 July 2013, when it hosted the Love Ball, a fundraising gala event organised by the Naked Heart Foundation.

The Salle Garnier had to shut its doors in 2000 for necessary repairing, renovation and restoration and after the $ 34 million completion the project under the leadership of Alain-Charles Perrot, the Chief Architect for France’s Historical Monuments, the iconic edifice reached a new height, when a five ton chandelier was entirely rebuilt and the windows overlooking the Mediterranean opened for the first time, making it the only opera house in the world to feature exterior views from the inside. The renewed opera house was reopened in November 2005, on the occasion of Prince Albert II’s accession to the throne, with a performance of The Journey to Reims, by Rossini.