The Royal Danish Orchestra (Det Kongelige Kapel) is a Danish orchestra based in Copenhagen. The Danish name for the orchestra indicates its original function as an ensemble geared to supplying the music for court events. The orchestra traces its origins back to 1448 and the Trumpet Corps at the royal court of King Christian I, and thus has claims to be the oldest orchestra in the world.

Over the years, the orchestra moved out of the court and settled down in the pit at the Royal Danish Theatre. Its leaders included Christoph Willibald Gluck, who composed the music for special occasions such as the celebration of the birth, in 1749, of the later King Christian VII, whilst in Denmark. A growing number of engagements saw an increase in the size of the orchestra. When Johan Gottlieb Naumann carried out his reforms in the 1780s, the ensemble numbered 46 members. At this time, the Chorus of the Royal Danish Opera became permanently assigned to the Royal Danish Theatre. F.L.Æ. Kunzen introduced Mozart into the ensemble's repertoire in the 1790s.