In heraldry, the ichthus, or fish symbol, is a direct emblem of Christian faith, baptism, discipleship, and spiritual identity. The word ichthus comes from the Greek for “fish,” and early Christians famously used the fish as a discreet sign of belief, later interpreting the Greek letters as an acronym for “Jesus Christ, Son of God, Savior.” In coats of arms, ecclesiastical badges, seals, and institutional arms, the ichthus can therefore stand for confession of faith, evangelism, charity, and the life-giving waters of baptism. Its simple outline makes it modern in appearance, but its meaning is ancient.

The ichthus is closely related to the broader heraldic use of fish. Fish in armory may refer to rivers, fishing rights, maritime trade, abundance, or local geography, but when shown in a clearly Christian context the meaning becomes devotional. It may appear with a cross, waves, a chalice, a bishop’s staff, or other sacred charges to mark a church, school, religious community, or charitable institution. The symbol is especially fitting for organizations dedicated to Christian education, mission, or pastoral care, since the Gospels call the apostles to become “fishers of men,” a phrase that gave fish imagery lasting religious force.

The ichthus is more common in modern ecclesiastical and institutional design than in medieval family armory, where naturalistic fish were more typical. Still, it follows heraldic principles when drawn as a charge, badge, or emblem in clear tinctures. Useful context can be found through the Heraldry Society, the College of Arms, and examples of fish charges at Heraldry of the World. In heraldry, the ichthus offers a concise and recognizable statement of Christian witness, renewal through water, and faithful service.