Catechism of the Catholic Church §316 — excerpt
Though the work of creation is attributed to the Father in particular, it is equally a truth of faith that the Father, Son and Holy Spirit together are the one, indivisible principle of creation.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.