This longitudinal study of midage women has two main aims: to examine the effect of disordered eating (DE) on quality of life (QoL) among women, including a comparison with a younger cohort and to investigate the mediating roles of both depressive symptoms and social support on the longitudinal relationship between DE and QoL as potential mechanisms of action. We used self-report data from six waves of the Australian Longitudinal Study on Women's Health over 14 years. A total of 12,338 women participating in the midage cohort (aging from 45-50 to 59-64) provided self-report indications of DE at Surveys 1 and 2, and QoL (SF-36 component scales-mental [MCS] and physical [PCS]) at Surveys 2-6. DE was reported by 10.98% of the women; this group also reported significantly poorer mental and physical QoL than those without DE, and this effect was sustained over time. Comparison with a parallel analysis of a younger cohort of women showed that the effect on midage women's physical QoL is greater than that of the younger women. The relationships between baseline DE and changes in QoL (both physical and mental) over time were mediated by levels of depressive symptoms and of social support over time. This study underscores the significant effect of DE on QoL in midage, an effect which is partially or fully mediated by depressive symptoms or social support. Well-being of midage women with indicators of DE needs to be supported by tailoring prevention and interventions activities specifically for this group.