The Prix Royal-Oak is a Group 1 flat horse race in France open to thoroughbreds aged three years or older.
It is run at Longchamp over a distance of 3,100 metres (about 1 mile and 7½ furlongs), and it is scheduled to take place each year in late October.
It was named after Royal Oak (foaled 1823), a key stallion in the establishment of thoroughbred breeding in France.
The present system of race grading was introduced in 1971, and the Prix Royal-Oak was classed at the highest level, Group 1.
Formerly France's equivalent of the St Leger Stakes in England, the Prix Royal-Oak was opened to horses aged four or older in 1979 and to geldings in 1986.