Find readings for Catholic Mass in the Liturgical Calendar published by the United States Conference of Catholic Bishops. Those readings are the same each week all over the world, regardless of location. The only differences that are permitted are occasional divergences for local celebrations.
The readings at Catholic Mass are contained in the Lectionary, which is the book that is used for the scripture readings at Catholic liturgies. The mass readings are promulgated by the Vatican and may not be changed except in certain detailed circumstances for local observances. The readings for Sunday follow a three-year schedule (Years A, B and C) and include four readings (one Old Testament Reading, one Psalm, one New Testament reading from the Epistles or Acts of the Apostles, and one Gospel reading). Weekday readings follow a different schedule and include three different readings. On weekdays, one reading from the Old Testament and one from the Psalms follow a two-year schedule, and the lone daily Gospel reading follows a one-year schedule.
The readings of the Roman Catholic Mass, as presented in the Lectionary, are the basis of many other liturgical systems, including the Revised Common Lectionary, which is used by many Protestant churches as of 2015.