Phineas Flynn: A notable friend of Phineas is Isabella, a girl around his age living across the street from his current place of residence. His relationship with her as a friend has proven to be very durable, however he is almost completely (if not absolutely) oblivious of her love and admiration for him.

As an incurable optimist, Phineas constantly looks on the brighter side of things. He is also extremely smart, creative, persistent, and able to endeavor in immensely large projects and activities with the help of his stepbrother. His hospitality is a driving force behind many of his plans.