Background: Body-related teasing is known to be linked to body dissatisfaction and dieting behavior in adolescents. However, little is known about it in non-Western countries. This study aims to examine the prevalence of body-related teasing among Japanese adolescents and its connection to weight status, body image, and dieting behavior to consider implications for public health. Methods: The design of this study is a cross-sectional study. An anonymous self-administrated survey was conducted with 1172 junior high school students in Higashi-Osaka City in Osaka Prefecture in Japan. The sampling method was non-random design. The survey items included self-reported height and weight, history and source of teasing, body image perception, and dieting behavior. A chi-square test and logistic regression analysis were used to examine the associations. Results: A history of teasing was reported by 16.4% of boys and 32.5% of girls (P < 0.001, effect size = 0.19). The most common answer for source of teasing was friends (84.7% of boys’ teasing, 67.1% of girls’ teasing, P = 0.003, effect size = 0.19). Students who were overweight, of an upper-normal weight status, and perceived themselves as "fat" were at a greater risk of being teased. Additionally, students with a history of teasing were significantly likelier to display dieting behavior (odds ratios with confidence intervals: boys 4.06 [2.08–7.93], girls 2.40 [1.53– 3.75]). Conclusion: Body-related teasing has a significant association with body image and dieting behavior in Japanese adolescents. A school-based education should be provided to reduce body-related teasing.