Richard Olivier de Longueil, French Roman Catholic bishop and cardinal (died 1470)

Richard Olivier de Longueil (1406–1470) was a French Roman Catholic bishop and cardinal.

A bishop is an ordained member of the clergy who is entrusted with a position of authority and oversight in a religious institution. In Christianity, bishops are normally responsible for the governance and administration of dioceses. The role or office of the bishop is called episcopacy or the episcopate. Organisationally, several Christian denominations utilise ecclesiastical structures that call for the position of bishops, while other denominations have dispensed with this office, seeing it as a symbol of power. Bishops have also exercised political authority within their dioceses.

A cardinal is a senior member of the clergy of the Catholic Church. As titular members of the clergy of the Diocese of Rome, they serve as advisors to the pope, who is the bishop of Rome and the visible head of the worldwide Catholic Church. Cardinals are chosen and formally created by the pope, and typically hold the title for life. Collectively, they constitute the College of Cardinals. The most solemn responsibility of the cardinals is to elect a new pope in a conclave, almost always from among themselves, with a few historical exceptions, when the Holy See is vacant.