A variety of studies have examined ways in which cognitive and social-emotional factors may be linked to and affected by hearing loss, use of cochlear implants (CIs), and sign language. A related domain that largely has been overlooked, however, is personality. This paper reports a study of personality traits and self-efficacy among deaf and hard-of-hearing (DHH; n = 223) college students, with and without CIs, as compared to hearing peers (n = 106). All participants completed (HEXACO) personality trait and self-efficacy inventories; DHH participants also completed a communication questionnaire. Hearing participants scored higher on the personality trait Conscientiousness than both DHH CI users and non-CI users, as well as higher on Openness to Experience compared to DHH CI users. Hearing participants also scored higher on self-efficacy compared to DHH non-CI users. Among DHH non-CI users, greater self-rated sign language skills were associated with higher Extraversion and Agreeableness scores. Among the DHH CI users, earlier sign language acquisition was associated with higher Openness to Experience scores, and earlier cochlear implantation was associated with greater Emotionality scores. Self-efficacy was associated with both better self-rated spoken language skills and a stronger preference for spoken language over sign language use among DHH CI users.