Chaldean Eparchy of Saint Peter the Apostle (Latin: Eparchia Sancti Petri Apostoli urbis Sancti Didaci Chaldaeorum) is a Chaldean Catholic Church eparchy of the Catholic Church in the Western United States.

It is exempt, i.e. immediately subject to the Holy See, not part of any ecclesiastical province.

It was created by Pope John Paul II on 21 May 2002 on territory split off from the Chaldean Catholic Eparchy of Saint Thomas the Apostle of Detroit, also exempt, and the only other Chaldean Catholic diocese in the USA.

The Eparchy of St. Peter The Apostle comprises four vicariates consisting of its member parishes.

The fourth vicarate comprises the vocational housing of the non-diocesan religious life within the Eparchy.