The association between personality traits and motivational units, such as life goals, has been a longstanding interest of personality scientists. However, little research has investigated the longitudinal associations between traits and life goals beyond young adulthood. In the present study (N=251) we examined the rank-order stability of, and mean-level changes in, the Big Five and major life goals (Aesthetic, Economic, Family/Relationship, Hedonistic, Political, Religious, Social) from college (age 18) to midlife (age 40), as well as their co-development. Findings showed that personality traits and major life goals were both moderately-to-highly stable over 20 years. On average, there were mean-level increases in the Big Five and mean-level decreases in life goals over time. Patterns of co-development suggest people formulate goals consistent with their personality traits, and conversely, investing in goal-relevant contexts is associated with trait change. We discuss the results in light of Social Investment Theory and the developmental regulation literature.