Wellness is defined as an individual's lifestyle, choices, and habits as a way to achieve optimal health and well-being. Professional organizations and literature in the counseling field underscored the importance of enhancing personal wellness of professional counselors and counselors-in-training. The assumption underlying this movement was that counselors' personal wellness would be directly translated into their effectiveness with clients in counseling practice. However, this assumption has received little empirical attention. In addition, the review of counselor wellness literature illustrated the need for addressing potential moderators in the relationship of counselor wellness to counseling effectiveness as an attempt to provide an elaborated knowledge base for wellness interventions in counselor training. Thus, this study investigated the relationship of Korean counselors' personal wellness to their clients' perceptions of counseling effectiveness and the moderating effects of counselor empathy on this relationship. Participants in this study were 133 counselor-client dyads who had engaged in face-to-face individual counseling at university counseling centers or youth counseling institutes located in Seoul and Gyeonggi Province, South Korea. Survey measures for counselors were used for the assessment of personal wellness, empathy, and social desirability. Client survey measures were used to assess counseling effectiveness variables: (a) satisfaction with counselors' in-session behavior, (b) evaluation about the session impact, and (c) perception of the working alliance. The results from correlation and multiple regression analyses indicated that Korean counselors' personal wellness scores were not significantly related to their clients' ratings of counseling effectiveness. However, a series of hierarchical regression analyses revealed that Korean counselors' cognitive empathy moderated the relationships of their personal wellness to client-perceived counseling effectiveness. Specifically, the findings suggested that, for Korean counselors with lower levels of cognitive empathy, wellness in Essential Self had a positive influence on client-perceived session smoothness, but wellness in Coping Self had a negative effect on client-rated working alliance. Also, wellness in Creative Self was found to have a negative influence on client-perceived session smoothness only among Korean counselors with higher levels of cognitive empathy. These findings call into question the supposition that well counselors are more likely to be effective with their clients, suggesting that a more complicated interplay between counselor wellness and other potential moderators should be considered as a determinant of counseling effectiveness. Future research is warranted to see if this study's findings are replicated with American counselor samples. Limitations are presented with a focus on range restrictions on the counseling effectiveness variables and small effect sizes associated with the interactions. In light of these limitations, future research directions are also discussed.