The fleur-de-lis (also spelled fleur-de-lys; plural fleurs-de-lis or -lys) is used in heraldry, where it is particularly associated with France.

The name, anglicized, means "lily flower", and the symbol is in fact a stylized lily flower. It was adopted by King Philip I of France in the 11th century. His grandson Louis VII was the first to adopt the Azure semé-de-lis Or (a blue shield with a tight pattern of small golden fleur-de-lis) as his badge, and this came to be so closely associated with his country that it is now known as the "France Ancient". Three gold flowers on a blue background ("France Modern") dates to 1376 and Charles V of France.

The Fleur-de-lis origins with French monarchs stems from the baptismal lily used in the crowning of King Clovis I. To further enhance its mystique, a legend eventually sprang up that the a vial of oil descended from heaven to anoint and sanctify Clovis as King. The thus "anointed" Kings of France later maintained that their authority was directly from God, without the mediation of either the Emperor or the Pope. Other legends claim that even the lily itself appeared at the baptismal ceremony as as a gift of blessing in an apparition of the Blessed Virgin Mary. The Catholic Church later endorsed the legend by associating Mary with the symbol.

By the 14th century it had become so closely associated with the rule of France that the English king Edward III quartered his coat of arms with France Ancient in order to emphasize his claim on the French crown. This quartering was changed to France Modern in the early 1400s. The fleur-de-lys was not removed until 1801, when George III gave up his formal claim to the French throne.

France Modern remained the French royal standard, and with a white background was the French national flag until the French Revolution, when it was replaced by the tri-colour flag of modern-day France. The fleur-de-lis was restored to the French flag in 1814, but replaced once again after the revolution against Charles X of France in 1830 It is retained on the flag of Quebec to the present day.

Other notable places or institutions that use the symbol informally or as part of their heraldic arms are: Quebec; Canada; Augsburg, Germany; Florence, Italy; Laško, Slovenia; the Fuggers medieval banking family; Bosniaks in Bosnia and Herzegovina; the Boy Scouts; New Orleans, Louisiana, and Louisville, Kentucky.