The Catechism of the Catholic Church, in the section on the Characteristics of Faith, describes faith as a grace
The Glossary that the United States Conference of Catholic Bishops appended to their edition of the Catechism of the Catholic Church describes faith as a theological virtue given by God as grace:
Faith: Both a gift of God and a human act by which the believer gives personal adherence to God who invites his response, and freely assents to the whole truth that God has revealed. It is this revelation of God which the Church proposes for our belief, and which we profess in the Creed, celebrate in the sacraments, live by right conduct that fulfills the twofold commandment of charity (as specified in the ten commandments), and respond to in our prayer of faith. Faith is both a theological virtue given by God as grace, and an obligation which flows from the first commandment (26, 142, 150, 1814, 2087).
St. Paul, in 1 Corinthians 12:4-9, describes faith as a gift given by the Holy Spirit:
4 Now there are varieties of gifts, but the same Spirit; 5 and there are varieties of service, but the same Lord; 6 and there are varieties of working, but it is the same God who inspires them all in every one. 7 To each is given the manifestation of the Spirit for the common good. 8 To one is given through the Spirit the utterance of wisdom, and to another the utterance of knowledge according to the same Spirit, 9 to another faith by the same Spirit, to another gifts of healing by the one Spirit,