The Feast of Christ the King (or properly, the Solemnity of Christ the King) is a holy day in the liturgical calendar of the Roman Catholic Church, and also some Protestant churches.

Prior to 1970, the feast was observed on the last Sunday in October. However, the reformed calendar approved by the Second Vatican Council that took effect in that year changed the date to the last Sunday before the next liturgical year's Advent begins (Advent marking the start of the liturgical year). Before this change, the Sunday before Advent bore the designation "Last Sunday After Pentecost" and had its own special mass, regardless of the number of Sundays there were between Pentecost and Advent (23 to 28) in that particular year. Many of the same readings used in this mass were incorporated into the mass authorized for the feast of Christ the King in its new location in the calendar.

The current Christ the King feast will fall on whichever day from November 20 through November 26, all inclusive, is a Sunday in a given year. It is reckoned as the 34th and

White vestments are worn at masses on this Sunday, rather than the green that prevails during the rest of Ordinary Time, except for those observances (solemnities or feasts) that call for either white or red.

In the calendar used in some localities by the Methodist Church, the feast of Christ the King is the last Sunday of Kingdomtide, and falls on the same Sunday as in the Catholic calendar.

The former date of the Christ the King feast — the last Sunday in October — is observed as Reformation Sunday by many Protestant denominations. Christus Koning van het Heelal