Antonio is Leonato’s brother. An old man, he has a tendency to wag his head in a characteristic way. He apparently has a son who provides for the music in Leonato’s house.
When a servant tells him that Don Pedro intends to woo Hero, he rushes to tell his brother, who is slightly skeptical of the thought. After the disaster in the church, he begins by playing the level-headed part, attempting to calm Leonato down, but when they are confronted by the prince and Claudio, he is incapable of restraining himself and loses his temper, insulting both Claudio and Don Pedro so severely than Leonato must attempt to calm him down in return. He has a very traditional view of the family that does not seem quite sure of how to deal with Beatrice, rarely addressing her.