The Prix de Royaumont is a Group 3 flat horse race in France open to three-year-old thoroughbred fillies.
It is run at Chantilly over a distance of 2,400 metres (about 1½ miles), and it is scheduled to take place each year in late May or early June.
It was initially reserved for fillies considered below the standard required for the Prix de Diane, which used to be run on the same day.
The Prix de Royaumont was abandoned throughout World War I, with no running from 1915 to 1918.
A new schedule was introduced in 1978, and the race was moved to a date earlier than that of the Prix de Diane.