Two experiments examined relations among social maturity, executive function, language, and cochlear implant (CI) use among deaf high school and college students. Experiment 1 revealed no differences between deaf CI users, deaf nonusers, and hearing college students in measures of social maturity. However, deaf students (both CI users and nonusers) reported significantly greater executive function (EF) difficulties in several domains, and EF was related to social maturity. Experiment 2 found that deaf CI users and nonusers in high school did not differ from each other in social maturity or EF, but individuals who relied on sign language reported significantly more immature behaviors than deaf peers who used spoken language. EF difficulties again were associated with social maturity. The present results indicate that EF and social maturity are interrelated, but those relations vary in different deaf subpopulations. As with academic achievement, CI use appears to have little long-term impact on EF or social maturity. Results are discussed in terms of their convergence with findings related to incidental learning and functioning in several domains.