The Pontifical Equestrian Order of Saint Sylvester (Latin: Ordo Sancti Silvestri Papae, Italian: Ordine di San Silvestro Papa), sometimes referred to as the Sylvestrine Order, or the Pontifical Order of Pope Saint Sylvester, is one of five orders of knighthood awarded directly by the Pope as Supreme Pontiff and head of the Catholic Church and as the Head of State of Vatican City. It is intended to honour Catholic laypeople who are actively involved in the life of the Church, particularly as it is exemplified in the exercise of their professional duties and mastership of the different arts. The order has been bestowed upon members of other Christian denominations as well, in addition to those of other religions.

This Order was at one time united with the Order of the Golden Militia. Pope Pius X in his motu proprio of 7 February 1905, entitled Multum ad excitandos, divided the Sylvestrine Order into two Orders of Knighthood, one retaining the name of St. Sylvester and the other taking the ancient name of the Order, i.e. Order of the Golden Militia, or Order of the Golden Spur.

It is intended to honour Catholic laypeople who are actively involved in the life of the Church, particularly as it is exemplified in the exercise of their professional duties and mastership of the different arts. It is also conferred on non-Catholics, with recipients including members of other Christian denominations, such as Anglicans, as well as those of other religions, including Muslims and Jews. The Knights of Saint Sylvester used to have the privilege of riding a horse inside Saint Peter's in Rome, the same privilege accorded to the other major pontifical orders.

Awards of the Order are generally made on the recommendation of Diocesan Bishops or of Apostolic Nuncios (nominations may be made by parish priests to their bishop for his consideration). Awards are also granted on recommendation of the Papal Secretary of State. In 1994 Pope John Paul II extended membership in the Order to ladies as well as gentlemen.

Prior to 1841, it was known as the Militia of the Golden Spur or Golden Militia, and though it is not historically established who among the many supposed founders is the true one, yet it undoubtedly is the oldest and, at one time, was one of the most prized of the papal orders. Faculties granted to the Sforza family, to the College of Abbreviators, and to bishops assistant at the throne to create Knights of the Golden Militia resulted in lavish bestowal and diminished prestige of the decoration.

Pope Gregory XVI in his Papal Brief of 31 October 1841, entitled Quod hominum mentes, retained the ancient name of the Order and placed it under the patronage of St. Sylvester (one of its alleged founders). He withdrew all faculties to whom and by whomsoever given, and forbade the use of the title or the decoration to all knights created by any means other than a Papal Brief. To restore the Order to its ancient glory and splendour, he limited the number of Commanders to 150 and knights to 300 (for the Papal States only), and appointed the Cardinal of Apostolic Briefs as Chancellor of the Order, with the duty of preserving the name, grade, number and date of admission of each knight.

Pope Gregory divided the Order into two classes:

The Order currently has four classes. In order of seniority, they are: