Chagnoald (Cagnoald, Cagnou) (died 633 AD) was a Frankish bishop of Laon during the 7th century.
The food ran out and all he and the young monk Chagnoald had to eat were crab apples.
Columban ordered him to go back to the orchard and to divide it in two halves, one for the bear and one for the monks.
Chagnoald left his see, finding refuge in the territory of the king's brother Theudebert II, and worked with Columbanus as a missionary in the area of Lake Constance.
On the death of Columbanus, Chagnoald returned to his old diocese, and resumed his duties as bishop.