Pope Pius IX instituted the liturgical feast of Saint Catherine of Siena in the Roman Calendar.
On 30 April 1866, Pope Pius IX formally instituted the liturgical feast of Saint Catherine of Siena within the General Roman Calendar, ensuring that her memory would be liturgically celebrated by the universal Church rather than solely through regional or Dominican devotion.
This institutional step, coming more than four centuries after her canonization, reflected the enduring and even growing significance of Catherine's cult within Catholic devotional life during the nineteenth century, a period marked by renewed interest in medieval mystics and saints as the Church navigated modern political and intellectual challenges.
The establishment of a universal feast day meant that Catherine's example, as a laywoman, mystic, and reformer, would be presented annually to the entire Catholic world through the liturgy, sermons, and devotional readings. While her feast is now generally kept on 29 April, the anniversary of her death, in most modern calendars, this 1866 institution was a formative step in the standardization of her liturgical commemoration.
This recognition reinforced Catherine's position within the pantheon of officially venerated saints and set the stage for further honors in the following century, including her proclamation as co-patron of Italy in 1939 and her declaration as a Doctor of the Church in 1970.