Appalachian women face significant health disparities and have limited access to health care. Mental health conditions and treatment-seeking are stigmatized in Appalachian communities. Appalachian women may benefit from web-based interventions targeting less stigmatized health complaints (e.g., insomnia), while simultaneously yielding benefit in associated mental health conditions including symptoms of post-traumatic stress disorder (PTSD). In this study, 37 trauma-exposed adult women aged 45 and older from rural Appalachian Kentucky completed a six-session online self-administered cognitive behavioral therapy for insomnia (CBT-I) intervention and completed measures of PTSD symptoms, insomnia, and depression at pre- and post-treatment. Participants reported a significant reduction in PTSD symptoms from pre- to post-intervention, and this remained significant after adjusting for severity of insomnia and depression pre-treatment. Pending replication in a randomized controlled trial, web-based CBT-I may offer an adjunctive mental health treatment option that circumvents cultural stigmas and reduces PTSD symptoms for trauma-exposed Appalachian women.