In the canon law of the Catholic Church, a mission sui iuris (Latin: missio sui iuris, pl. missiones sui iuris), also known as an independent mission, can be defined as: "an ecclesial structure erected from a previous territory, with explicit boundaries, under the care of a religious community or other diocese, responding to a missionary exigency and headed by a superior nominated by the Holy See, under the aegis of the Congregation for the Evangelization of Peoples."
It is generally applied to an area with very few Catholics, or in areas where Christianity (in particular Roman Catholicism) is either outlawed or undergoing persecution, often desolate or remote, and ranks below an apostolic prefecture and an apostolic vicariate.
