Hero 

A beautiful attractive lady.

She falls for Claudio almost instantly and is crudely betrayed by the men in play.

When Claudio accuses her of betrayal she suffers terribly.

Leonato

A respected and well to do noble.

The action of the play takes place in his home in Messina, Italy.

As governor of Messina he is second in power only to Don Pedro.

Claudio

 A very young soldier who has won great acclaim fighting under Don Pedro.

He falls quickly in love with Hero and appears to be a fool in love when Don John deceives him.

His immature attitude allows him to reject Hero as quickly as he accepts her, and he is hasty when he believes the rumours and takes his revenge on their wedding day.