There are many explanations available concerning the circle that’s present in a Celtic cross. Some believe that the circle symbolizes eternity and the unending bounty of God’s love. Some people believe that the circle represents a halo, in particular, a halo that encircles the head of Jesus. And some people believe that the circle represents the hope of salvation.

All of these meanings can be valid.

According to legend the origin of the circle itself can be attributed to St. Patrick who decided that combining a circle with a cross would be more appealing to the Irish non-believers that he was trying to convert to Christianity. It’s believed that while preaching, he saw a sacred stone symbol that was marked with a circle representing the moon goddess. St. Patrick added the mark of a Latin cross to the stone circle and blessed it, thus creating the first Celtic cross. Some naysayers discount this legend because it means that a Christian priest used heathen Druid symbolism to faction a sacred Christian symbol however it’s documented that St. Patrick did indeed convert many former Druids into Christians, even ordaining some of them as priests. It’s not too hard to imagine that he took something that the Druids were comfortable with and could relate to (the sun symbol) and used it to make their conversion to Christianity more palatable.

For more information see:

Celtic Cross Tattoos: What Do They Mean?

Celtic Butterfly Tattoos