Bud Caldwell is Bud, Not Buddy’s protagonist and main character. He is the book’s first person narrator, and the reader experiences the story from Bud’s point of view. Toward the end of the story, Bud is given a new name, Sleepy LaBone, by those who have become his family. This naming marks a new family and a new beginning for Bud.

When the reader first meets Bud, he is living at the Home, an orphanage in Flint, MI. At the age of six, Bud had discovered his momma, lifeless on her bedroom floor. His first words, “HERE WE GO AGAIN,” betray his distrust in the system and the adults who manage it. He has minimal power over his situation and must go where others send him. In the past four years, ten-year-old Bud he has been shuffled around foster homes and is on his way to the third. He’s no longer able to cry—"the tears don’t come anymore”—but  he endears the reader to him when he demonstrates tenderness in comforting six-year-old Jerry, who has also received the news about his first foster home.

Bud’s greatest desire is to find a family and a place to belong. After his horrible experience at the Amos foster home, Bud escapes the system and attempts to travel from Flint to Grand Rapids, Michigan to find his father. Smart and resourceful, Bud uses the clues he believes his momma left for him, namely a blue flyer he carries in his suitcase, to track the likely whereabouts of his father. Along the way, Bud doesn’t trust adults easily, and at first he only asks for help from those who had a connection to his momma, such as the librarian. As the story progresses, Bud learns to accept the help of others who extend kindness to him, either because he doesn’t have a choice or because they don’t seem to have any ulterior motives. These trusted adults include his pretend father and mother, from the mission’s food line, and Lefty Lewis. Bud learns, especially when he meets Miss Thomas and the band members, that there are adults out there who have his best interests at heart.

Momma had instilled in Bud a sense of hope and optimism, making sure he understood that “when one door closes, … another door opens.” She  also emphasized that his name was Bud, not Buddy. His name is a metaphor for his growing sense of self throughout the story, a bud like a flower “waiting for just the right warmth and care to open it up.” Bud’s humor, wit, and penchant for telling a great story make him a very likable character.