The Catholic League of France (French: Ligue catholique), sometimes referred to by contemporary (and modern) Catholics as the Holy League (La Sainte Ligue), was a major participant in the French Wars of Religion. The League, founded and led by Henry I, Duke of Guise, intended the eradication of Protestantism from Catholic France, as well as the replacement of the French King Henry III, who had acquiesced to Protestant worship in the Edict of Beaulieu (1576). The League also fought against Henry of Navarre, the Protestant prince who became presumptive heir to the French throne in 1584.

Pope Sixtus V, Philip II of Spain, and the Jesuits were all supporters of this Catholic party.

Local confraternities were initially established by French Catholics to counter the Edict of Beaulieu in 1576. King Henry III placed himself at the head of these associations as a counter-balance to the ultra-Catholic League of Peronne. Following the repudiation of that edict by the Estates General, most of the local leagues were disbanded.

In June 1584, the illness and death of Henry III's heir François, Duke of Anjou made the Protestant Henry of Navarre the new heir presumptive under Salic law. Faced with the prospect of a Protestant king, Catholic nobles gathered at Nancy in December 1584, and the League drew up a treaty with Philip II's ambassadors at Joinville. Following this agreement, the Catholic confraternities and leagues were united as the Catholic League under the leadership of Henry I, Duke of Guise.

The Catholic League aimed to preempt any seizure of power by the Huguenots, who made up nearly half of the French nobility, and to protect French Catholics' right to worship. The Catholic League's cause was fueled by the doctrine Extra Ecclesiam nulla salus. It feared that the House of Valois would weaken the Catholic position by attempting to appease the Huguenots.

The League was also inspired by the writings of the English Catholic refugee Richard Verstegan, who published accounts of the suffering of English, Welsh, and Irish Catholic Martyrs under the Protestant monarchy of England. In 1588, Verstegan was briefly imprisoned by Henri III at the insistence of the English ambassador Sir Francis Walsingham, but soon released at the insistence of the Catholic League and the Papal Nuncio.

By this time "the League in Paris had fallen from its first ideals into mere partisanship", and the Duke of Guise increasingly used it not only to defend the Catholic cause, but as a political tool in an attempt to usurp the French throne.

Catholic Leaguers saw their fight against Calvinism (the primary branch of Protestantism in France) as a Crusade against heresy and to defend French Catholics from Elizabethan-style persecution. The League's pamphleteers blamed any natural disaster as God's way of punishing France for tolerating heretics.