<p>This study aimed to identify lifestyle and biological factors associated with body image among reproductive-aged women, focusing on physical activity, sedentary time, sleep, BMI, premenstrual symptoms (PMS), and sleep quality. A secondary aim was to explore interrelationships among these factors to contextualise their combined association with body image. In this cross-sectional online survey, 291 women aged 18–45 years participated (mean age: 27.16 ± 0.36 years). Validated questionnaires were used to assess body image (Body Appreciation Scale), physical activity (Global Physical Activity Questionnaire), sleep quality (Sleep Quality Scale), BMI, and PMS (Premenstrual Assessment Form-Short Form). Data were analysed with IBM SPSS 28.0 using multivariable linear regression and correlation analyses (<i>p</i> &lt; 0.05). Higher BMI, greater PMS severity, poorer sleep quality and longer sedentary time were significantly associated with lower body appreciation. Correlations were found between PMS and sleep quality (<i>r</i> = 0.309; <i>p</i> &lt; 0.001), PMS and work-related moderate activity (<i>r</i> = 0.119; <i>p</i> = 0.043), and sleep quality and work-related moderate activity (<i>r</i> = 0.169; <i>p</i> = 0.004). No significant associations were observed for recreational physical activity with PMS (<i>r</i>=-0.041; <i>p</i> = 0.544) or sleep quality (<i>r</i>=-0.040; <i>p</i> = 0.498). Body image in reproductive-aged women was associated with both lifestyle behaviours and biological symptom burden. The findings suggest that supporting positive body image may benefit from integrated approaches addressing sedentary behaviour, sleep quality and menstrual health alongside weight-related factors.</p>