The term Mother Church denotes several meanings within Christianity. By general understanding, it may refer to either a religious faith, or a church (Basilica, Parish, or community church) building which draws as a "mother" or principal source of faith or authority adhered to by its believers.

The word "Mother Church" (in its abstract form) is used as a reference to the Universal Church often used by Christians who relate it as the Bride of Christ.

This term is most often used among Roman Catholics as the Holy Mother Church or Sancta Mater Ecclesia (Lat.). It is used as "Designating the whole Christian Church or all Christians collectively."

By contrast in its concrete form, the mother church can refer to the Archbasilica of St. John Lateran (see below).

Bingham in 1855 writes "Ecclesia matrix, a mother-church, is sometimes taken for an original church planted immediately by the Apostles, whence others were derived and propogated afterward. ... And in this sense the Church of Jerusalem is called 'the mother-church of all churches in the world.'" He also refers to "Arles the mother church of France, because supposed to be planted by the Apostle's missionary Trophimus, first bishop of the place."