Bud Caldwell is a fictional character from the novel "Bud, Not Buddy" written by Christopher Paul Curtis. He is a ten-year-old boy living during the Great Depression, navigating life in an orphanage and foster homes. Bud is resourceful and determined, using his wits to survive and find his father. Throughout the story, Bud embarks on a journey to discover his family roots. He carries a suitcase filled with important items that represent his past. His adventures lead him to meet various characters, including musicians from the jazz era, which plays a significant role in his quest for belonging.