Self-concept has meaningful relations with psychological functioning and well-being across the life span. Hence, it is important to understand how and when individual differences in multiple domains of self-concept begin to stabilize and whether individual differences remain stable throughout childhood and adolescence and into early adulthood.We assessed individuals' (N = 372) scholastic, social, athletic, and physical appearance self-concepts at five waves over 20 years from age 4 to age 24.In general, stability was large, but medium-sized estimates were obtained for some domains over longer (e.g., 6-year) intervals. Indirect effects from preschool to early adulthood were small, but from age 14 to 24 were medium to large. Stabilities maintained significance independent of family socioeconomic status and global self-worth. Stability estimates were similar for boys and girls except over adolescence for scholastic self-concept, which was more stable for girls than boys.Multiple domains of self-concept constitute stable individual-difference characteristics, independent of global feelings of self-worth. Individuals who have high or low self-concepts early in development tend to maintain their relative standing into early adulthood suggesting points of intervention.