Optimism is associated with a number of positive health and life course outcomes among adults, yet less is known about the role of optimism during the formative early adolescent years. Using a strengths-based relational developmental systems model, this study explored the relation of dispositional optimism to individual-level characteristics and ecological assets in families, schools, and neighborhoods in a sample of early adolescents. Specifically, early adolescents' optimism, personal characteristics (i.e., depressive symptoms, anxiety symptoms, self-concept, positive behavior), and ecological assets (i.e., perceived parent support, parent knowledge, dinner with an adult family member, school adult support, school connectedness, neighborhood adult support, neighborhood safe places) were assessed in 1,250 4th to 7th graders from 23 public elementary schools in seven urban school districts. Correlational and hierarchical regression analyses suggested that positive self-concept, low depressive symptoms, and high perceived parental support and school connectedness were most strongly associated with adolescents' optimism. The importance of examining individual characteristics in conjunction with the relational features of early adolescents' environments when understanding optimism is discussed.