This study explored the effects of optimism, intrinsic motivation, and family relations on vocational identity in college students in the United States and South Korea. The results yielded support for the hypothesized multivariate model. Across both cultures, optimism was an important contributing factor to vocational identity, and intrinsic motivation partially mediated the link from optimism to vocational identity. In addition, family relations moderated the mediation effect of intrinsic motivation with American students but not Korean students. With Korean students, family relations moderated the direct link from optimism to vocational identity. These results have significant implications for counseling to promote vocational identity development for diverse college students.