This cross-sectional study examined correlates of self-esteem, happiness, and body image in Turkish secondary school students. A convenience sample of 377 secondary school students completed measures related to self-esteem, happiness, and body image. Data were analyzed using descriptive statistics and multivariate analysis of variance. The results of this study suggested that a higher grade point average was positively associated with higher self-esteem among secondary school students. The findings also indicated that being older, having a large number of same sex and opposite-sex friends, a high level of self-confidence, participating in leisure time physical activities, and experiencing any stressful life events were also positively associated with higher levels of happiness. Lastly, the results revealed that being male, being older, having a large number of same sex and opposite-sex friends, having a girl/boyfriend, a higher grade point average, and a high level of self-confidence were associated with positive body image in Turkish secondary school students. These research findings may help to determine distinct and shared correlates of self-esteem, happiness, and body image that could aid in the development of evidence-based positive psychology intervention programs for secondary school students.