The Prix de Royallieu is a Group 1 race run under Weight For Age conditions for fillies and mares at Longchamp conducted by France Galop.

The Prix de Royallieu is run over 2800m.

It was a Group 3 race in 1971 and shortened from 3000m to 2500m in 1972. It became Group 2 and moved to Arc weekend in 1988 after being in late October before that.

Originally it was for all sexes, it became a fillies race in 1922 and for mares in 1965.  As of 2019, it was elevated to Group 1 status making it the eighth major on Prix de l'Arc de Triomphe weekend.

The event is named after Royallieu, an area where high profile politician and owner/breeder Frederic de Lagrange stables were located in the late 19th century.

The 2016 and 2017 editions were run at Chantilly as Longchamp was under its long term redevelopment.

The Juliet Rose is the only multiple winner with two in 2016 and 2017.

1977 winner Trillion would graduate to take a Prix Ganay and a Prix Foy amongst other features.

Daryakana won the race in 2009 then ventured to Hong Kong where she took out the Hong Kong Vase against the males.

Making it a G1 generated a top field in 2019 with the Epsom Oaks winner Anapurna saluting.

Aussie champion mare Verry Elleegant had been left out of the Arc by handicappers the week before so ran in the 2022 Royallieu but she failed to impress.

Gerald Mosse and Frankie Dettori have six wins as a jockey while Alain de Royer-Dupre has eight as a trainer.

Grateful won for Ballydoyle in 2024. She was out of the great American mare Tepin who won a Queen Anne plus many G1s in the US.

The last non-French winner was Grateful in 2024 for Aidan O'Brien.

The Prix de Royallieu was worth €300,000 in 2024.

Notable winners of the Prix de Royallieu include Sea La Rosa (2022), Loving Dream (2021), Wonderful Tonight (2020), Anapurna (2019), The Juliet Rose (2016/2017), Ebiyza (2013), Daryakana (2009), Anna Pavlova (2007) and Trillion (1997).

The 2024 Prix de Royallieu was won by Grateful from River Of Stars and Mistral Star.