The Canon of the Mass, also known as the Canon of the Roman Mass and in the Mass of Paul VI as the Roman Canon or Eucharistic Prayer I, is the oldest anaphora used in the Roman Rite of Mass. The name Canon Missæ was used in the Tridentine Missal from the first typical edition of Pope Pius V in 1570 to that of Pope John XXIII in 1962 to describe the part of the Mass of the Roman Rite that began after the Sanctus with the words Te igitur. All editions preceding that of 1962 place the indication "Canon Missae" at the head of each page from that point until the end of the Mass; that of 1962 does so only until the page preceding the Pater Noster and places the heading "Ordo Missae" on the following pages.

The Mass of Paul VI, also known as the Ordinary Form or Novus Ordo, is the most commonly used liturgy in the Catholic Church. It was promulgated by Pope Paul VI in 1969 and its liturgical books were published in 1970; those books were then revised in 1975, they were revised again by Pope John Paul II in 2000, and a third revision was published in 2002.