St. Gabriel the Archangel is most well-known as the angel present at the Annunciation to Mary, inviting Mary to say "Yes" to God's divine plan.
At the same time, he is often invoked for his angelic protection, asking him to defend the Church from the evil spirits roaming around the world.
Here is a prayer from Dom Prosper Gueranger's Liturgical Year that asks for his special protection against evil.