On what date in 1973 did the official opening ceremony take place?

The Sydney Opera House’s official opening ceremony took place on 20 October 1973. Queen Elizabeth II formally opened the building during a nationally televised ceremony attended by a large crowd.

The event included fireworks and a performance of Beethoven’s Ninth Symphony. It marked the public culmination of a project that had begun construction in 1959 and had faced extraordinary engineering challenges, political disputes, delays, and cost increases.

The date is sometimes confused with earlier performances held inside the building. The first public Concert Hall concert took place on 5 September 1973, while the first opera in the Opera Theatre was performed on 28 September. Those events preceded the formal opening; they were not the official inauguration of the completed Opera House.