Background. Bullying is a major school problem. Victims of bullying often experience low self-esteem, whereas social skills are positively associated with the level of self-esteem. This research examined whether the victim’s condition impacted their social skills and self-esteem. Methods. International school students in Thailand aged 13 to 18 years old completed the Olweus bullying questionnaire, social capital questionnaire (SC), social skills questionnaire (SS), adolescent discrimination index (ADDI), and the Rosenberg self-esteem scale (RSES). Moderation analyses and visual presentations were carried out using IBM SPSS ver. 22 and PROCESS, ver. 4.0. Results. A total of 102 students participated (63% female). The mean age of the participants was 16.57 (SD = 1.42). The number of victims was 16 (15.7%), the mean (SD) for the SC, SS, ADDI, and RSES was 7.82 (2.37), 44.45 (9.40), 12.33 (9.82), and 27.85 (5.31), respectively. As predicted, those with high social skills reported greater self-esteem when they had never been bullied. The moderation effect was significant: B = 0.458, standard error = 0.203, 95% CI = −0.836 to −0.054. Additionally, the ADDI and SC were found to predict self-esteem. Conclusions. The significant moderation effect suggests the importance of identifying the victim’s condition when the association between social skills and self-esteem is not observed (as expected) among school adolescents. A longitudinal study to confirm the causal relationship should be encouraged. Further research on providing appropriate interventions along with social skill training for the victim group is warranted.