The Miraculous Medal (French: Médaille miraculeuse), also known as the Medal of Our Lady of Graces, is a devotional medal, the design of which was originated by Saint Catherine Labouré following her apparitions of the Blessed Virgin Mary in Rue du Bac, Paris, France. It was made by goldsmith Adrien Vachette. According to the teaching of the Catholic Church, the use of sacramentals such as this medal prepares people to receive grace and disposes them to cooperate with it

Catherine Labouré stated that on 18 July 1830, the eve of the feast of Saint Vincent de Paul, she woke up after hearing the voice of a child calling her to the chapel, where she heard the Virgin Mary say to her, “God wishes to charge you with a mission. You will be contradicted, but do not fear; you will have the grace to do what is necessary. Tell your spiritual director all that passes within you. Times are evil in France and in the world.”

On 27 November 1830 Catherine reported that the Blessed Mother returned during evening meditations. She displayed herself inside an oval frame, standing upon a globe. She wore many rings set with gems that shone rays of light over the globe. Around the margin of the frame appeared the words Ô Marie, conçue sans péché, priez pour nous qui avons recours à vous (“O Mary, conceived without sin, pray for us who have recourse to thee”).

 As Catherine watched, the frame seemed to rotate, showing a circle of twelve stars, a large letter M surmounted by a cross, and the stylized Sacred Heart of Jesus crowned with thorns and Immaculate Heart of Mary pierced with a sword. Asked why some of the gems did not shed light, Mary reportedly replied, “Those are the graces for which people forget to ask.” Sister Catherine then heard the Virgin Mary ask her to take these images to her father confessor, telling him that they should be put on medallions, and saying “All who wear them will receive great graces.”

Sister Catherine did so, and after two years of investigation and observation of Catherine’s ordinary daily behaviour, the priest took the information to his archbishop without revealing Catherine’s identity. The request was approved, and medallions were designed and produced through goldsmith Adrien Vachette.

The chapel in which Saint Catherine experienced her visions is located at the mother house of the daughters of Charity in Rue du Bac, Paris. The incorrupt bodies of Saint Catherine Labouré and Saint Louise de Marillac, a co-founder of the Congregation of the Daughters of Charity of Saint Vincent de Paul, are interred in the chapel, which continues to receive daily visits from Catholic pilgrims today.

Pope John Paul II used a slight variation of the reverse image as his coat of arms, the Marian Cross, a plain cross with an M underneath the right-hand bar (which signified the Blessed Virgin at the foot of the Cross when Jesus was being crucified).