The Prix Vicomtesse Vigier is a Group 2 flat horse race in France open to thoroughbreds aged four 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 May.
The event was established in 1859 and named after the Viscountess Vigier. It was originally the second leg of a pair of races called the Prix Biennal. The first leg, for three-year-olds, was created a year earlier. The version for older horses was initially contested over 3,200 metres. It was cancelled because of the Franco-Prussian War in 1871, and it was cut to 3,000 metres in 1897. It was abandoned throughout World War I, with no running from 1915 to 1918.
Both legs of the Prix Biennal were given a new title, the Prix Jean Prat, in 1940. This was in memory of Jean Prat (1847–1940), a successful racehorse owner and breeder. The older horses' version was held at Maisons-Laffitte from 1943 to 1945, and on the first occasion it was contested over 3,100 metres. It returned to Longchamp in 1946, and its regular distance was extended to 3,100 metres in 1955.
The Prix Jean Prat for older horses was renamed the Prix Vicomtesse Vigier in 1985. This was in honour of Vicomtesse Vigier, Madeleine Double de Saint-Lambert (1869–1970), the niece of Jean Prat, who inherited her uncle's stable upon his death. The version for three-year-olds continued with the title Prix Jean Prat.
The Prix Vicomtesse Vigier used to be held several weeks before the Prix du Cadran, but that race was switched from May to October in 1991. The leading contenders often go on to compete in the latter event, and the last to win both in the same year was Vazirabad in 2017.
Most successful horse (3 wins):
Leading jockey (6 wins):
Leading trainer (7 wins):
Leading owner (5 wins):