Several cross‐sectional studies have confirmed the negative correlation between depressive symptoms and life satisfaction; however, there exists limited research on this longitudinal relationship. This study employed the random‐intercept cross‐lagged panel model (RI‐CLPM) to examine the longitudinal reciprocal relationship between depressive symptoms and life satisfaction. For this purpose, a nationally representative sample of middle‐aged women (N = 2,054 at baseline, aged 40–60 years) from the Korean Welfare Panel Data (KoWePS) was analysed. The results of the RI‐CLPM indicate that at the within‐person level, an individual's life satisfaction levels negatively predicted depressive symptoms, and vice versa. This finding indicates that interventions to reduce depressive symptoms may help improve life satisfaction. Conversely, interventions to increase life satisfaction may help to reduce or prevent depressive symptoms. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.