The Feast of the Sacred Heart (properly the Solemnity of the Sacred Heart or the Feast of the Most Sacred Heart of Jesus) is a feast in the liturgical calendar of the Roman Catholic Church. It falls 19 days after Pentecost, on a Friday. The earliest possible date is 29 May, as in 1818 and 2285. The latest possible date is 2 July, as in 1943 and 2038.

Devotion to the Sacred Heart of Jesus can be clearly traced back at least to the eleventh century. It marked the spirituality of Bernard of Clairvaux in the twelfth century and of Bonaventure and Gertrude in the thirteenth. The beginnings of a devotion toward the love of God as symbolized by the heart of Jesus are found even in the fathers of the Church, including Origen, Ambrose, Jerome, Augustine of Hippo, Hippolytus of Rome, Irenaeus, Justin Martyr and Cyprian, who used in this regard John 7:37-39 and John 19:33-37.^[1]