A credo (pronounced , Latin for "I Believe") is a statement of religious belief, such as the Apostles' Creed. The term especially refers to the use of the Nicene-Constantinopolitan Creed (or less often, the Apostles' Creed) in the Mass, either as spoken text, or sung as Gregorian chant or other musical settings of the Mass.

A credo is a statement of belief, especially of a religious nature. Often it refers to the Nicene Creed or Apostles' Creed in particular.